title: Clinical application of fluorescence endoscopic imaging using hypericin for the diagnosis of human oral cavity lesions.
abstract: BACKGROUND
  Diagnosis of oral cancer is conventionally carried out using white light endoscopy and histopathology of biopsy samples. However, oral tumours are mostly superficial and the lesion and its margins can be difficult to visualise under white light. We present clinical data on fluorescence diagnostic imaging of oral lesions using hypericin, a plant-based photosensitiser.
  
  
  METHODS
  Fluorescence images of lesions and normal tissue were captured using an endoscope after hypericin administration. The images were analysed to extract their colour parameters, which, along with the red-to-blue intensity ratios, were analysed and used to discriminate between tissue types. The results were correlated with those from histopathology.
  
  
  RESULTS
  The red-to-blue intensity ratio increased from normal to hyperplastic to cancerous tissue and was a good parameter to discriminate between these tissue types, with sensitivity and specificity levels of 90% and above.
  
  
  CONCLUSIONS
  Our results show that hypericin fluorescence imaging has the potential to be used for the clinical diagnosis of oral cancer. Further study to enhance the clinical potential of this technique includes the development of a real-time image processing and analysis system interfaced to the endoscope to enable same-day cancer diagnosis and demarcation of lesion margins in a clinical setting.
authors.affiliation: Division of Medical Sciences, National Cancer Centre Singapore, 11 Hospital Drive, Singapore 169610, Singapore. dmsmcd@nccs.com.sg
authors.forename: P S P
authors.initials: PS
authors.lastname: Thong
authors.forename: M
authors.initials: M
authors.lastname: Olivo
authors.forename: W W L
authors.initials: WW
authors.lastname: Chin
authors.forename: R
authors.initials: R
authors.lastname: Bhuvaneswari
authors.forename: K
authors.initials: K
authors.lastname: Mancer
authors.forename: K-C
authors.initials: KC
authors.lastname: Soo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000873:Anthracenes; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis; D003952:Diagnostic Imaging / Q000379:methods*; D004724:Endoscopy; D005260:Female; D005453:Fluorescence; D006801:Humans; D006965:Hyperplasia; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000473:pathology; D009062:Mouth Neoplasms / Q000175:diagnosis*; D010569:Perylene / Q000031:analogs & derivatives*
chemical_list: D000873:Anthracenes; D010569:Perylene; C004965:hypericin