PHOTODYNAMIC THERAPY LIGHT SOURCES

Photodynamic therapy light sources include Blu-U, ClearLight, IPL and different forms of lasers. All photodynamic therapy reactions require specific light wavelengths that are within the absorption spectrum of the specific photosensitizing / photodynamic drug. The longer wavelengths have more energy and are able to penetrate deeper into tissue. For example, 630 nm wavelength will penetrate the skin 5 mm. 700 - 800 nm wavelengths will penetrate 2 cm !! into the skin.

Peak absorption of photodynamic therapy drugs, such as aminolevulinic acid is at 409 nm, a safe wavelength, but not completely. Blue light, which is the most commonest light wavelength used, is 417 nm. Others that are commonly used are in the low to high 500 nm's.