Laser Diode System For Interstitial Photodynamic Therapy

Interstitial Photodynamic Therapy (IPDT) is a promising form of treatment of deep-seated and bulky malignant tumors, based on the lethal cell response to the photochemical reactions when drug is light activated at presence of oxygen. After intravenous administration, the drug is retained selectively by malignant cells, and then, the light is delivered to the target tissue through multiple optical fibers. In order to accomplish an effective internal illumination, laser sources are preferably used because of two important reasons: the laser beam is easily focused to optical fibers, and the monochromatic light can be confined to the narrow absorption band of the drug. In this work we present the design of an irradiation laser system, which involves a 635nm laser diode and a delivering fiber system, for 5-ALA mediated IPDT.