photodynamic therapy (PDT)

Treatment with drugs that become active when exposed to light (photosensitizers).

During PDT, the photosensitizer is applied to the skin or injected into a vein and cancer cells absorb it. After a period of time, the cancer cells are exposed to light, which activates the photosensitizer and destroys the cancer cells.

Also called photochemotherapy, photoradiation therapy and phototherapy.