What is Photodynamic Therapy?

Photodynamic therapy (PDT) is a treatment that uses a photosensitizing medication activated by light to kill abnormal skin cells or skin cancer cells. The medication only works after being “turned on” by certain kinds of light.

PDT can only treat areas where light can reach. As a result, it’s mainly used to treat problems on or just under the skin. Because light cannot penetrate deeply through body tissues, PDT cannot be used to treat cancers that have grown deeply into the skin or other organs.

PDT is becoming more widely recognized as a valuable treatment option for certain precancers and types of localized skin cancers (cancers that have not spread far from where they started).

What are the benefits of PDT?

Studies have shown that PDT works well in treating certain kinds of cancers and pre-cancers. Some of the benefits of PDT are:
• No long-term side effects when used properly
• Less invasive than surgery
• Short treatment sessions with fast recovery
• Precisely targeted treatment
• Low risk of permanent marks or scars
• May cost less than other cancer treatments


What should I expect with PDT?

First the skin is cleaned, and the light-sensitive medication is applied in the clinic to the desired zones on the skin. In some cases, particularly thick areas are siphoned off prior to application of the medication. The photosensitizing medication is then absorbed by the skin cancer cells over a period of minutes to several hours. The light is then applied to the area to be treated. The light stimulates activation of the absorbed medication which destroys the precancerous or cancerous cells. This also triggers the immune system to help attack the precancerous or cancerous cells.

PDT will result in light sensitivity for up to 48 hours following treatment, so protection from the sun and fluorescent lights is necessary.

For questions about photodynamic therapy and what to expect, speak to your clinician.