title: Fluorescence induced with 5-aminolevulinic acid for the endoscopic detection and follow-up of esophageal lesions.
abstract: BACKGROUND
  The aim of this study was to investigate the use of orally administered 5-aminolevulinic acid (ALA) for in vivo photodynamic diagnosis and follow-up of premalignant and malignant esophageal lesions.
  
  
  METHODS
  Twenty-two patients with known or treated malignant and precancerous esophageal lesions were sensitized with orally administered ALA (15 mg/kg). Six patients had Barrett's esophagus, with or without severe dysplasia, 5 squamous cell cancer or early-stage (uT1N0M0) adenocarcinoma, 1 advanced-stage (uT3N1) adenocarcinoma, and 1 patient a lesion with an appearance that suggested esophageal cancer. Nine patients underwent photodynamic diagnosis for follow-up after treatment of esophageal cancer with curative intent; 6 had no macroscopically visible lesion and 3 a barely visible lesion under standard (white-light) endoscopy. Photodynamic diagnosis was conducted 6 to 7 hours after oral administration of ALA by using a special light source capable of delivering either white or violet-blue light. Red fluorescence was detected with a charged coupled device camera attached to a fiberoptic endoscope. Corresponding endoscopic, fluorescence, and microscopic findings were compared.
  
  
  RESULTS
  By using histology as the reference standard (n = 86 biopsies), 85% of the biopsy sites with premalignant or malignant histopathology exhibited red fluorescence, whereas only 25% were detected with white-light endoscopy.
  
  
  CONCLUSIONS
  ALA-induced fluorescence might be useful for the early endoscopic detection of malignant esophageal lesions and follow-up after treatment of such lesions with curative intent.
authors.affiliation: Department of Medicine I, Friedrich-Alexander University Erlangen-Nuremberg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Mayinger
authors.forename: S
authors.initials: S
authors.lastname: Neidhardt
authors.forename: H
authors.initials: H
authors.lastname: Reh
authors.forename: P
authors.initials: P
authors.lastname: Martus
authors.forename: E G
authors.initials: EG
authors.lastname: Hahn
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000622:Aminolevulinic Acid / Q000008:administration & dosage; D001706:Biopsy; D004938:Esophageal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D004945:Esophagoscopy; D005260:Female; D005453:Fluorescence; D006801:Humans; D008297:Male; D008875:Middle Aged; D017319:Photosensitizing Agents / Q000008:administration & dosage; D011524:Protoporphyrins; D012680:Sensitivity and Specificity
chemical_list: D017319:Photosensitizing Agents; D011524:Protoporphyrins; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX