Wavelength dependent photodynamic effects on chemically induced rat bladder tumors following intravesical instillation of 5-aminolevulinic acid.

Abstract

The aim of the study was to determine photodynamic effects in chemically induced rat bladder tumors after intravesical instillations of 5-aminolevulinic acid (5-ALA) and PDT-dependence on laser wavelength and light dose. Following intravesical instillation of a 5-ALA solution (40 mg 5-ALA in isotonic saline and sodium-bicarbonate) rat bladder tumors have been treated with integral irradiation using laser light at wavelengths of lambda = 630 nm and lambda = 635 nm in a light dose range of 15 to 100 J/cm2. A significantly higher amount of necrosis including damage of normal urothelium was obtained in rat bladder tumors using laser light at lambda = 635 nm. For 5-ALA assisted photodynamic treatment of superficial bladder cancer in patients the irradiation wavelength of lambda = 635 nm is recommended.