Glossary Term:


photodynamic therapy




also called PDT. A treatment sometimes used for cancers of the skin, esophagus (swallowing tube), lung, or bladder. PDT begins with the injection of a non-toxic chemical into the blood. This chemical is allowed to collect in the tumor for a couple of hours to a couple of days, depending on the chemical. A special type of laser light is then focused on the cancer. This light causes the chemical to change so that it can kill cancer cells. The advantage of PDT is that it can kill cancer cells with very little harm to normal cells. The downside is that it can only be used in areas that can be reached with light.