What is photodynamic therapy?

This treatment method is used to open up esophageal blockages or treat small, shallow tumors in patients who cannot tolerate open surgery. In PDT, a drug called a photosensitizer is administered intravenously and preferentially absorbed by cancer cells over a few days. Using an endoscope, the surgeon exposes the lesion to a certain wavelength of light, which causes an active form of oxygen to be produced. This directly kills the cancer cells and also acts indirectly to damage the tumor's blood vessels, further destroying the cancer and limiting damage to surrounding healthy tissue. PDT cannot be used for large or deep tumors. Risks include light sensitivity for about six weeks after treatment, trouble swallowing after treatment, swelling, pain, or scarring in healthy tissue.

Surgeons may also place a stent in the esophagus to open up any blockage and enable more comfortable swallowing.

Photodynamic therapy (PDT) uses medicine that is activated with light to kill cells. It is used to treat an eye disease called macular degeneration, some cancers, and skin problems such as acne.

For PDT, a medicine, called the photosensitizer, is put near the cells that need to be destroyed. The photosensitizer may be put on the skin, taken by mouth, or given in a vein. Then the photosensitizer is "turned on" (activated) with light. The light used is often from a laser or from light-emitting diodes (LEDs). The specific wavelength of light activates the medicine to make a kind of oxygen that kills nearby cells.

Photosensitizers will make the skin and eyes sensitive to light for about 6 weeks after treatment. So people who have PDT need to avoid direct sunlight and bright indoor lights.