Treatment involves applying a cream-based sensitizer to the skin where the cancer is situated. The skin is covered and left to allow cancerous cells take up the sensitizer, but healthy cells do not. After about three hours, a 630nm wavelength light is shone onto the skin, which destroys any cells that have taken up the sensitizer (ie the cancerous cells). The skin can be reddened and sensitive afterwards, but it usually recovers within 1-2 weeks.
The advantages of PDT are that it treats early skin cancers that may not be apparent to the naked eye. There is virtually no scarring and the skin can appear rejuvenated and blemish free afterwards.