title: Noninvasive evaluation of oral lesions using depth-sensitive optical spectroscopy.
abstract: BACKGROUND
  Optical spectroscopy is a noninvasive technique with potential applications for diagnosis of oral dysplasia and early cancer. In this study, we evaluated the diagnostic performance of a depth-sensitive optical spectroscopy (DSOS) system for distinguishing dysplasia and carcinoma from non-neoplastic oral mucosa.
  
  
  METHODS
  Patients with oral lesions and volunteers without any oral abnormalities were recruited to participate. Autofluorescence and diffuse reflectance spectra of selected oral sites were measured using the DSOS system. A total of 424 oral sites in 124 subjects were measured and analyzed, including 154 sites in 60 patients with oral lesions and 270 sites in 64 normal volunteers. Measured optical spectra were used to develop computer-based algorithms to identify the presence of dysplasia or cancer. Sensitivity and specificity were calculated using a gold standard of histopathology for patient sites and clinical impression for normal volunteer sites.
  
  
  RESULTS
  Differences in oral spectra were observed in: (1) neoplastic versus nonneoplastic sites, (2) keratinized versus nonkeratinized tissue, and (3) shallow versus deep depths within oral tissue. Algorithms based on spectra from 310 nonkeratinized anatomic sites (buccal, tongue, floor of mouth, and lip) yielded an area under the receiver operating characteristic curve of 0.96 in the training set and 0.93 in the validation set.
  
  
  CONCLUSIONS
  The ability to selectively target epithelial and shallow stromal depth regions appeared to be diagnostically useful. For nonkeratinized oral sites, the sensitivity and specificity of this objective diagnostic technique were comparable to that of clinical diagnosis by expert observers. Thus, DSOS has potential to augment oral cancer screening efforts in community settings.
authors.affiliation: Department of Bioengineering, Rice University, Houston, Texas, USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Schwarz
authors.forename: Wen
authors.initials: W
authors.lastname: Gao
authors.forename: Crystal
authors.initials: C
authors.lastname: Redden Weber
authors.forename: Cristina
authors.initials: C
authors.lastname: Kurachi
authors.forename: J Jack
authors.initials: JJ
authors.lastname: Lee
authors.forename: Adel K
authors.initials: AK
authors.lastname: El-Naggar
authors.forename: Rebecca
authors.initials: R
authors.lastname: Richards-Kortum
authors.forename: Ann M
authors.initials: AM
authors.lastname: Gillenwater
mesh_terms: D000293:Adolescent; D055088:Early Detection of Cancer; D005336:Fiber Optic Technology; D005453:Fluorescence; D006801:Humans; D009055:Mouth / Q000473:pathology*; D009061:Mouth Mucosa / Q000473:pathology; D009062:Mouth Neoplasms / Q000175:diagnosis; D011230:Precancerous Conditions / Q000175:diagnosis; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000379:methods*