title: Photodetection of basal cell carcinoma using methyl 5-aminolaevulinate-induced protoporphyrin IX based on fluorescence image analysis.
abstract: BACKGROUND
  The preferential accumulation of 5-aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) in neoplastic cells supports its potential use in the photodetection of porphyrin fluorescence in tumour cells. Hence, epithelial tumours, including basal cell carcinoma (BCC), might be visualized using the fluorescence of selectively accumulated ALA-induced PpIX.
  
  
  OBJECTIVE
  In this study, we evaluated the clinical efficacy of PpIX fluorescence images using fluorescence image analysis (FIA) to define the lateral border between the tumour and tumour-free areas of facial BCC.
  
  
  METHODS
  FIA was used to define the lateral border between the tumour and tumour-free areas on red fluorescence images induced by the topical application of methyl 5-aminolaevulinate (MAL) ointment. According to the FIA results, 50 tissue samples, obtained from 10 patients with BCC, were divided into three categories: tumour area (n = 10), suspected tumour area (n = 20) and suspected tumour-free area (n = 20). These tissue samples were evaluated by histopathological examination. The FIA tool marked out the PpIX fluorescence image for defining the lateral border between the BCC tumour and tumour-free areas.
  
  
  RESULTS
  The rate of tumour detection from BCC lesions using PpIX fluorescence with the FIA tool showed a sensitivity of 94.1% and specificity of 82.6%.
  
  
  CONCLUSIONS
  These results suggest that MAL-induced PpIX fluorescence imaging using FIA is quite sensitive and specific for detecting tumour and occult tumour in facial BCC lesions. This method of presurgical in vivo imaging is therefore proposed as a useful tool for defining the lateral border between BCC tumour and tumour-free areas.
authors: Department of Dermatology, Chonnam National University, Gwangju, Korea.
authors: Y
authors: Y
authors: Won
authors: S H
authors: SH
authors: Hong
authors: H Y
authors: HY
authors: Yu
authors: Y H
authors: YH
authors: Kwon
authors: S J
authors: SJ
authors: Yun
authors: S C
authors: SC
authors: Lee
authors: J B
authors: JB
authors: Lee
mesh_terms: D000368:Aged; D000622:Aminolevulinic Acid / Q000031:analogs & derivatives*; D002280:Basal Cell Carcinoma / Q000175:diagnosis*; D005153:Facial Neoplasms / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017319:Photosensitizing Agents; D011524:Protoporphyrins / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; C475457:methyl 5-aminolevulinate; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX