<title>In vivo comparison of 630-nm laser and broad spectrum nonlaser light for topical 5-animolaevulinic acid photodynamic therapy</title>

Abstract

At present lasers are chosen in photodynamic therapy because they produce light of superior beam and spectral qualities and of more penetrating longer wavelengths. However there is stronger absorption by porphyrins at less penetrating shorter wavelengths. The response of a rat intradermal fibrosarcoma to topical 5-aminolaevulinic acid photodynamic therapy was compared using 630 nm light from a copper vapor/due laser or broad spectrum red or white light from a modified slide projector. When the tumors were between 2 - 3 mm thick they were randomized to treatment with one light source at a range of fluences all at the same sub- hyperthermic fluence rate. Laser light and white light produced a greater tumor growth delay than broad spectrum red light, and at higher fluences white light was comparable to laser light. For the treatment of thin, superficial tumors using topical aminolaevulinic acid photodynamic therapy an inexpensive, portable, white light source may be an effective alternative to a laser.