Photodynamic therapy for non-melanoma skin cancer

Some people with non-melanoma skin cancer have photodynamic therapy (PDT). It uses photosensitizer drugs to destroy cancer cells. These drugs make cells sensitive to light.

PDT may be used to treat:

• basal cell carcinoma (BCC) on the surface of the skin (superficial BCC)
• squamous cell carcinoma (SCC) in situ
• actinic keratosis, a precancerous condition of the skin

PDT is most often offered when surgery can’t be done or when other treatments will affect the appearance of the skin. In most cases, there is a higher risk of the cancer coming back (recurring) after PDT than after surgery. But PDT usually changes the skin's appearance less than surgery does. Your healthcare team will consider this when deciding to offer PDT.

PDT is given in 2 stages. First, you are given the photosensitizer drug. It is applied to the abnormal area as a cream or gel. All cells absorb the photosensitizer, but it stays in the cancer cells longer than it does in normal cells. The photosensitizer drugs that may be used for non-melanoma skin cancer are:

• methyl aminolevulinate (Metvix)
• aminolevulinic acid (Levulan)

After a certain amount of time, cancer cells containing the photosensitizer are exposed to a low-intensity red light, blue light or regular daylight when outside. The photosensitizer in the cancer cells absorbs the light and a chemical reaction kills the cancer cells. Most normal cells are not affected.

Tell your healthcare team if you have side effects that you think are from PDT. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.

PDT may cause these side effects:

• sensitivity to light of the skin (called photosensitivity), which usually lasts 4 to 6 days after treatment or longer
• pain in the area you were given PDT, including burning and stinging
• red, itchy skin
• swelling (edema)