Photodynamic Therapy

This is a technique for treatment of sunspots and some superficial skin cancers. It involves application of Metvix cream which gets taken up into abnormal skin cells where it is then chemically converted to a new compound which is reactive to light.

Your doctor applies the cream at the centre. After the cream has soaked in for 1-3 hours your doctor shines a specially designed red light on the area of skin that is being treated and this causes a reaction in the abnormal skin cells which causes their destruction. This treatment is called Photodynamic Therapy (PDT). A hot stinging sensation is felt during the application of the light which may require some local anaesthetic to be used. The area treated becomes red and may blister. A dressing is applied and you need to keep the area covered and protected from light for 48 hours. The dressing is then removed and the area washed and coated with moisturizing cream each day until the wound heals over the following 1-2 weeks. The cosmetic results are usually very good.

As an alternative to conventional PDT that uses the red light, it is now possible to use normal sunlight to activate the Metvix cream. This is called daylight PDT (dPDT). The main advantage of this technique is that the local discomfort felt during activation is signifiantly less than with the red light. It is mainly used for treatment of broad areas of sun damage and sunspots.