Photodynamic Diagnosis (5-Aminolevulinic Acid) of Transitional Cell Carcinoma After Bacillus Calmette-Guérin Immunotherapy and Mitomycin C Intravesical Therapy

Background: Photodynamic diagnosis (PDD) is a technique that enhances the detection of occult bladder tumors during cystoscopy using a fluorescent dye. Objective: To study the differential effects of bacillus Calmette-Guérin (BCG) and mitomycin C (MMC) intravesical therapy on the false-positive rate of PDD of bladder cancer. Design, setting, and participants: This study included 552 procedures and 1874 biopsies. Intervention: Tumors were resected and biopsies were taken from suspicious areas, under guidance of white-light endoscopy and 5-ALA (5-aminolevulinic acid)-induced fluorescence cystoscopy. Measurements: The influence of intravesical BCG immunotherapy and intravesical MMC chemotherapy on pyuria, inflammation, and PDD specificity was examined in univariate analyses. Results and limitations: BCG significantly results in inflammation (odds ratio [OR]: 1.53, p = 0.002), leukocyturia (OR: 1.84, p = 0.034), and false positives in PDD (OR: 1.49, p = 0.001). However, a single BCG instillation within 3 mo before PDD is most likely not associated with increased false-positive rates (OR: 0.35, p = 0.26). Leukocyturia normalizes within 6 wk after the last BCG instillation, but PDD specificity is reduced up to 3 mo. Conclusions: BCG is an important predictor for false positives in PDD (5-ALA). More than one BCG instillation within 3 mo before fluorescence cystoscopy decreases the specificity of PDD.