Pre-malignancies and skin malignancies
Photodynamic therapy (PDT) is FDA-approved for the treatment of both pre-malignancies (actinic keratoses) and Bowen’s Disease, a superficial form of squamous cell carcinoma that appears as a persistent red scaly patch. PDT is especially useful for widespread lesions on the face and scalp. The cure rate with PDT is comparable to that of surgery but the cosmetic outcome is much better.
What this process involves is the application of a cream called METVIX (Methyl Levulanic Acid) which is applied to the affected area. This cream is then covered to allow absorption into the skin and left on for a period of 3-4 hours. It is important to note that the cream will be taken up only by abnormal cells. Following this time, the dressing is removed and the area is exposed to a very strong visible red light. The energy from this light results in activation of the cream to produce oxygen radicals which then selectively target only the atypical cells while causing minimal damage to the surrounding normal tissue. The atypical cells are destroyed and this can cause some discomfort. For this reason, pre-meds are given prior to the procedure and you will be unable to drive yourself home.
After the procedure, you must strictly avoid sunlight for at least 48 hours as UV exposure will potentiate the activation of the medication and cause a more severe reaction. Directly following the procedure, it will feel like you have a bad sunburn. This is then followed by some swelling, crusting and oozing.
We will hold your hand through the recovery period and make sure that you are comfortable at all times. The area will heal in around 1-2 weeks and although you will not look your best during this time, the end result will be worth it. Even once you have recovered from the acute scabbing, it can take six weeks or even longer for the pinkness to resolve. We will then examine the treated area again to gauge response to treatment.
