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Photodynamictherapyhasthreekeycomponents:photosensitizer,oxygen,andlaserlight.Thephotosensitizeritselfisnon-toxicuntilexcitedbylightofa ...

Principle Photodynamic therapy (PDT) is an ablation technique used to treat various forms of superficial cancer. A photosensitizer is used in conjunction with a light source with emission at a specific wavelength (e.g. 630 nm). The light activates photosensitizer accumulated in tumor tissue, which results in the death of tumor cells through the production of reactive oxygen species (ROS).

PDT therapy begins with the patient taking photosensitizer orally, intravenously, or topically. Photosensitizer tends to localize in tumor tissue at concentrations higher than those in normal tissue. A light source of a specific wavelength is then used to excite the photosensitizer to produce ROS, a toxic singlet oxygen and free radicals that are cytotoxic to cancer cells. Photodynamic therapy also induces capillary endothelial damage and blood clots which cause microcirculatory disorders and lead to further necros...