Fluorescence detection of bladder tumors with 5-amino-levulinic acid

BACKGROUND: Preliminary data suggest that photodiagnosis by fluorescence detection of protoporphyrin IX, a biosynthetic product of the photosensitizer 5-amino-levulinic acid (ALA), is superior to conventional cystoscopy in bladder tumor detection. PATIENTS AND METHODS: We instilled 1.5 g of ALA into the bladders of 52 patients with suspect bladder lesions 1 to 4 hours prior to transurethral resection or biopsy. Red fluorescence was induced by violet-blue light (wavelength 380-450 nm). RESULTS: In 13 patients (25%), significant tumors were detected by fluorescence that were missed on conventional cystoscopy. In the present series, ALA photodetection had a sensitivity of 94.6% (compared with 76% for cystoscopy) and a specificity of 43%. CONCLUSION: Fluorescence diagnosis with ALA may become a standard procedure for bladder tumor detection and resection, especially in endoscopically difficult situations (carcinoma in situ, multifocal tumors, multiple prior resections, or previous drug instillation therapy).