Role of 5-aminolevulinic acid in the detection of urothelial premalignant lesions.
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.
Zaak
Dirk
D
Department of Urology, Klinikum Grosshadern, Ludwig-Maximilians-University of Munich, Germany. dirk.zaak@uro.med.uni-meunechen.de
Hungerhuber
Edwin
E
Schneede
Peter
P
Stepp
Herbert
H
Frimberger
Dominic
D
Corvin
Stefan
S
Schmeller
Nikolaus
N
Kriegmair
Martin
M
Hofstetter
Alfons
A
Knuechel
Ruth
R
Knöchel
Ruth
R
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*
D014408:Biomarkers, Tumor; D000622:Aminolevulinic Acid