Photodynamic therapy (PDT) is a treatment used for superficial types of skin cancer. PDT is effective in treating actinic keratoses and superficial basal cell carcinomas. It may also be used for treatment of small, thin, low-risk nodular basal cell carcinomas outside of the head and neck area.

PDT utilizes photosensitizing agents, oxygen, and light to create a photochemical reaction that selectively destroys cancer cells. Photosensitizing agents are drugs that are administered into the body through topical methods. In the body, they concentrate in cancer cells and only become active when light of a certain wavelength is directed onto the area where the cancer is found. The photodynamic reaction between the photosensitizing agent, light and oxygen kills the cancer cells.