5-aminolevulinic acid in photodynamic diagnosis and therapy of urological malignancies.

Completeness and certainty of tumor detection are very important issues in clinical oncology. Recent technological developments in ultrasound, radiologic and magnetic resonance imaging diagnostics are very promising, but could not improve the detection rate of early stage malignancies. One of the most promising new approaches is the use of 5-aminolevulinic acid, a potent photosensitizer, in photodynamic diagnosis and therapy. 5-aminolevulinic acid is meanwhile a well-established tool in the photodynamic diagnosis of bladder cancer. It has been shown to improve the sensitivity of detection of superficial tumors and carcinoma in situ, which enables to reduce the risk of tumor recurrence related to undetected lesions or incomplete transurethral resection of the primary lesions. The use of 5-aminolevulinic acid is steadily expanding in diagnostics of urological malignancies. First clinical results are now reported in detection of urethral and ureteral lesions as well as in urine fluorescence cytology. Furthermore, due to the selective accumulation in transitional cell carcinoma of the bladder, 5-aminolevulinic acid may be an ideal candidate for photodynamic therapy in superficial bladder cancer. Summarizing the data of multiple clinical trials, 5-aminolevulinic acid is a promising agent in photodynamic diagnostics and treatment of superficial bladder cancer.