Photodynamic therapy (PDT) destroys cancer cells by using a drug called a photosensitizer, which makes the cells sensitive to laser light. PDT is a fairly new procedure and was approved for use in Canada in the 1990s. It is used:
PDT is usually done in stages:
A range of tests may be done before PDT, depending on the area being treated. Preparations similar to endoscopic procedures or conventional surgery may be needed. The photosensitizer makes the skin and eyes sensitive to strong indoor or outdoor light (photosensitive) for 4 to 6 weeks or more after treatment, so special precautions need to be taken.
PDT may be used with other cancer treatments such as surgery, chemotherapy or radiation therapy. Tumours that regrow and start to cause problems again can be retreated with PDT.