[Tumor recurrence prevention using photodynamic therapy after treatment of bladder cancer]

Photodynamic therapy with hematoporphyrin derivative was given to 21 patients with recurrent transitional cell carcinoma of the bladder. Each patient received red light (630nm) derived from a gold-vapor laser machine into the bladder. The light dose was given to the whole bladder by using the bulb diffuser with power density ranging from 36 to 72J/cm2. All patients had a complete response at 6 months. Three of the 21 patients had tumor recurrence at 12 months. This new light delivery system appears to be effective in the prevention of bladder cancer. Photochemotherapy is as useful as bladder chemotherapy. Its preventive effect will be elevated if it is repeated 6-12 months after first treatment.