Blue light photodynamic therapy is a form of photodynamic therapy that utilizes blue light and a chemical called aminolevulinic acid to treat actinic keratosis, a skin condition that can develop into cancer, according to the American Cancer Society. The drug is applied onto the skin, and the light results in a chemical reaction that kills cells.
Blue light photodynamic therapy involves applying the acid onto actinic keratosis lesions for 14 to 18 hours, explains the American Cancer Society. After this time, the blue light is applied to the area, activating the acid and causing it to react with oxygen and kill any cells. As the area is exposed to the light, stinging or burning may occur, along with redness of the skin, all of which is temporary.
Photodynamic therapy in general is an alternate method to treat some cancers, specifically skin cancers, notes the American Cancer Society. Unlike other methods such as surgery or chemotherapy, photodynamic therapy has no long-term side effects and is much less invasive. It is also very precise and can be repeated multiple times on the same region. However, it is usually only effective with specific cancers that are still localized, or with precancer such as actinic keratosis. Benefits include its ease of access and recognition as a situational treatment method.