Principles of the photodynamic therapy and its impact on the immune system.

Abstract

Photodynamic therapy (PDT) is an encouraging procedure for treatment and diagnosis of a wide variety of malignant processes. There are three main mechanisms by which tumors are destroyed during PDT: direct cell destruction, damage to the vascular stroma and immune elimination. PDT of high intensity, targeted to a large number of cells results in immunosuppression. Low dose/energy or localized PDT stimulates the immune response against the tumor. The review reports recently performed animal experimental studies as well as the first human clinical studies.