title: Role of 5-aminolevulinic acid in the detection of urothelial premalignant lesions.
abstract: BACKGROUND
  The authors evaluated the role of 5-aminolevulinic acid (5-ALA)-induced fluorescence endoscopy (AFE) in the detection of flat urothelial lesions in light of the suggestions made for flat neoplastic lesions within the 1999 World Health Organization (WHO) classification of urinary bladder tumors.
  
  
  METHODS
  From 1995 to 2000, 713 patients underwent 1414 AFE procedures for the detection of transitional cell carcinoma of the bladder (TCCB). Fluorescence imaging was performed with an incoherent light source (D-light; 380-440 nm) that was filtered for efficient protoporphyrin IX excitation and with cystoscopes partially blocking reflected excitation light to enable fluorescence evaluation by a red/blue color contrast 2-3 hours after 50 mL of a 3% solution of 5-ALA was instilled into the bladder. In total, 3834 biopsy specimens (mean, 2.7 specimens per AFE procedure) were taken.
  
  
  RESULTS
  Malignant disease was found in 1250 (32.6%) of all biopsies, with 304 biopsies (24.3%) showing carcinoma in situ (cis) and dysplasia II degrees (dys II) according to the previous diagnostic criteria of the WHO. Under prior conventional white-light endoscopy, 30.3% of specimens with dys II and 52.8% of specimens with cis had been missed.
  
  
  CONCLUSIONS
  The current results suggest that 5-ALA may be more effective in the detection of flat urothelial lesions than the current diagnostic devices.
authors.affiliation: Department of Urology, Klinikum Grosshadern, Ludwig-Maximilians-University of Munich, Germany. dirk.zaak@uro.med.uni-meunechen.de
authors.forename: Dirk
authors.initials: D
authors.lastname: Zaak
authors.forename: Edwin
authors.initials: E
authors.lastname: Hungerhuber
authors.forename: Peter
authors.initials: P
authors.lastname: Schneede
authors.forename: Herbert
authors.initials: H
authors.lastname: Stepp
authors.forename: Dominic
authors.initials: D
authors.lastname: Frimberger
authors.forename: Stefan
authors.initials: S
authors.lastname: Corvin
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Schmeller
authors.forename: Martin
authors.initials: M
authors.lastname: Kriegmair
authors.forename: Alfons
authors.initials: A
authors.lastname: Hofstetter
authors.forename: Ruth
authors.initials: R
authors.lastname: Knuechel
authors.forename: Ruth
authors.initials: R
authors.lastname: Knöchel
mesh_terms: D000622:Aminolevulinic Acid / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001706:Biopsy; D002278:Carcinoma in Situ / Q000175:diagnosis; D002295:Carcinoma, Transitional Cell / Q000175:diagnosis*; D004724:Endoscopy; D006801:Humans; D011230:Precancerous Conditions / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis*
chemical_list: D014408:Biomarkers, Tumor; D000622:Aminolevulinic Acid