Guthrie Photodynamic Therapy Program

Abstract

Photodynamic therapy has been approved by the FDA for treatment of lung and esophageal cancer, pre-cancerous skin lesions and macular degeneration. Many other cancers are under study. Therapy begins with sensitization of abnormal tissue with injection of a light absorbing photoactive medication that is inert until exposed to light of a specific wavelength which induces free-radical formation and thromboxane-2 generation, destroying intracellular organelles. Light penetration is 4 to 8 mm, so repeat therapy is often needed. It is curative for some early cancers and an important adjunct in others.