Photodynamic therapy (PDT) is used for treatment of a variety of cancerous and precancerous conditions. Medications called photosensitizers are used to make cancer cells and other abnormal cells vulnerable to high-intensity light energy.
After the photosensitizer is applied to the skin topically, the physician exposes the cancer cells to a specific wavelength and energy of light that activates the drug and destroys the cancerous or precancerous cells.