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. The photosensitizer is nontoxic until it is activated by light. However, after light activation, the photosensitizer becomes toxic to the targeted tissue.

Several photosensitizer drugs are available today to treat a variety of diseases, including acne, psoriasis, age-related macular degeneration, and several cancers, such as skin, lung, brain, bladder, pancreas, bile duct, esophagus, and head and neck.

In addition to treating these conditions, PDT also helps treat bacterial, fungal and viral infections. Studies have shown that this light-based therapy can trigger the body's immune response, giving your body another means to help destroy cancerous and precancerous cells.

Why it's done

Photodynamic therapy is used to treat a variety of conditions, including:

  • Pancreatic cancer
  • Bile duct cancer (cholangiocarcinoma)
  • Esophageal cancer
  • Certain skin diseases, including precancerous skin changes (actinic keratosis) and nonmelanoma skin cancer
  • Lung cancer

Photodynamic therapy care at Mayo Clinic

March 05, 2022
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  3. Getting photodynamic therapy. American Cancer Society. https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/radiation/photodynamic-therapy.html. Accessed March 31, 2020.
  4. Cillo U, et al. Surgery for cholangiocarcinoma. Liver International. 2019; doi:10.1111/liv.14089.
  5. Wang KK, et al. The use of photodynamic therapy in pancreatic cancer: Consensus statement from an expert panel. Gastroenterology. 2017; doi:10.1016/S0016-5085(17)31842-5.
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  7. Wolfsen HC (expert opinion). Mayo Clinic. April 1, 2020.