title: In vivo autofluorescence spectroscopy of oral premalignant and malignant lesions: distortion of fluorescence intensity by submucous fibrosis.
abstract: OBJECTIVE
  To test whether autofluorescence spectroscopy can be used for the diagnosis of oral neoplasia in a high-risk population, we characterized the in vivo autofluorescence spectra from oral submucous fibrosis (OSF) lesions and oral premalignant and malignant lesions in both OSF and non-OSF patients.
  
  
  METHODS
  Autofluorescence emission spectra were measured under the excitation wavelength of 330 nm, using a Xenon lamp-based fluorospectrometer coupled to a handheld optical fiber probe. Autofluorescence spectroscopies were analyzed among patients with OSF lesions, and oral lesions of epithelial hyperkeratosis (EH), epithelial dysplasia (ED), and squamous cell carcinomas (SCC) and normal oral mucosa (NOM) of healthy volunteers.
  
  
  RESULTS
  We found that the most intensely autofluorescence emission peaks occurred at 380 nm and 460 nm. For comparing the spectral patterns among different groups of oral lesions and NOM, ratios of the area under the spectrum of 460+/-10 nm to that under the spectrum of 380+/-10 nm (denoted as A(460+/-10nm)/A(380+/-10nm)) were calculated. The mean ratio values increased gradually from OSF to NOM, to EH and ED, and to SCC. The ANOVA test showed significant differences in the ratio value among all categories of samples (P<0.01). On the other hand, we found that EH, ED, and SCC lesions on OSF patients had distorted autofluorescence intensity. The mean ratio values of EH, ED, and SCC between non-OSF and OSF patients show significant differences. Furthermore, an ANOVA test showed NOM is not distinguishable from EH and ED lesions on oral fibrotic mucosa (P>0.05).
  
  
  CONCLUSIONS
  Autofluorescence spectroscopy can be used to diagnose EH, ED, and SCC lesions in non-OSF patients but not in OSF patients.
authors.affiliation: Graduate Institute of Biomedical Materials, Taipei Medical University, Taipei, Taiwan.
authors.forename: Tsuimin
authors.initials: T
authors.lastname: Tsai
authors.forename: Hsin-Ming
authors.initials: HM
authors.lastname: Chen
authors.forename: Chih-Yu
authors.initials: CY
authors.lastname: Wang
authors.forename: Jui-Chang
authors.initials: JC
authors.lastname: Tsai
authors.forename: Chin-Tin
authors.initials: CT
authors.lastname: Chen
authors.forename: Chun-Pin
authors.initials: CP
authors.lastname: Chiang
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D009062:Mouth Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D009914:Oral Submucous Fibrosis / Q000000981:diagnostic imaging* / Q000473:pathology; D011230:Precancerous Conditions / Q000000981:diagnostic imaging* / Q000473:pathology; D011859:Radiography; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence