WAVELENGTH-DEPENDENT PHOTODYNAMIC EFFECTS ON CHEMICALLY-INDUCED RAT BLADDER-TUMORS FOLLOWING INTRAVESICAL INSTILLATION OF 5-AMINOLEVULINIC ACID

Purpose: The aim of the study was to determine photodynamic effects in chemically induced rat bladder tumors after intravesical instillation s of 5-aminolevulinic acid (5-ALA) and PDT-dependence on laser wavelen gth and Light dose. Material and Methods: Following intravesical insti llation of a 5-ALA solution (40 mg 5-ALA in isotonic saline and sodium -bicarbonate) rat bladder tumors have been treated with integral irrad iation using laser light at wavelengths of lambda = 630 nm and lambda = 635 nn in a light dose range of 15 to 100 J/cm(2).Results: A signifi cantly higher amount of necrosis including damage of normal urothelium was obtained in rat bladder tumors using laser Light at lambda = 635 nm. Conclusions: For 5-ALA assisted photodynamic treatment of superfic ial bladder cancer in patients the irradiation wavelength of lambda = 635 nm is recommended.