This treatment is effective for some superficial cancers such as superficial squamous & basal cell carcinomas, as well as actinic keratoses (also called solar keratoses) and has a lower risk of scarring compared with surgery.
A skin biopsy is sometimes required to confirm the diagnosis prior to treatment. The technique involves gently removing any crust from the lesion and applying a photosensitising cream. The cream contains an ingredient that is preferentially absorbed by the cancer cells and is sensitive to light. The light activates a chemical that destroys the cancer cells. Hence PDT selectively destroys the skin cancer whilst preserving the normal surrounding skin. On some occasions the PDT procedure is repeated to increase the cure rate. PDT provides an excellent cosmetic result as it has a lower risk of scarring compared with surgery and has a relatively high cure rate, but it can only be used on certain types of skin cancer.