Light emitting diode (LED) system for photodynamic therapy

Photodynamic therapy, PDT, has mainly been done clinically using laser systems. The use of lasers to treat cutaneous lesions is not necessary. In order to provide a more efficient and cost effective light source for the PDT treatment of cutaneous lesions, a clinical based light emitting diode (LED) system has been developed. The system include a tight density packing of AlGaAs high-brightness LEDs to produce incident irradiance values up to 200 MW/cm 2 . Initial systems have wavelengths of 665 nm and exhibit a bandwidth of 25 nm, FWHM. Other wavelengths are also possible. The system includes on-line dosimetry through an isotropic probe to permit the use to simply choose a dose, J/cm 2 . the system has been tested against a KTP/dye laser for the photosensitizer SnET2 to determine its equivalence to a monochromatic source.