• Therapy using oral or topical photosensitizing agents with subsequent exposure to light.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2021
• (photodynamic therapy) A medical treatment that uses a light source to activate a photosensitizing drug (one that becomes activated by light exposure). Often used in oncology, dermatology, and cosmetic surgery.
  Harvard Dictionary of Health Terms
  Harvard Medical Publishing, 2011
• (photodynamic therapy) Treatment with drugs that become active when exposed to light. These activated drugs may kill cancer cells.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• (photodynamic therapy) Use of light activated drugs (photosensitizing agents) to kill cancer cells.
  NCI Thesaurus
  U.S. National Cancer Institute, 2021
• (neoplasm/cancer photoradiation therapy) Intravenous administration of a photosensitizing agent which selectively concentrates in cancer cells, followed by exposure of the tumor to laser light of a specific wavelength; the resulting cytotoxic free radicals destroy the tumor.
  CRISP Thesaurus
  National Institutes of Health, 2006
• Photodynamic therapy (PDT) is a two-stage treatment that combines light energy with a drug (photosensitizer) designed to destroy cancerous and precancerous cells after light activation. Photosensitizers are activated by a specific wavelength of light energy, usually from a laser...
  Mayo Clinic
  Mayo Foundation for Medical Education and Research