Photodynamic therapy (PDT) has been an established treatment method for over 15 years in effectively dealing with precursors of non-melanoma skin cancer (actinic keratoses) and superficial basal cell carcinoma with light in combination with a photosensitizer.
The PDT is particularly well suited for the treatment of actinic keratoses, which are a frequent precancerous condition of squamous cell carcinoma (SCC). This is mainly caused by chronic UV light damage to the skin and is the most important risk factor for squamous cell carcinoma. In contrast to surgical excision, photodynamic therapy provides the advantage of being less invasive and causing less damage to the skin.
In the first session excess tissue is removed and the affected skin areas are perforated by using a fractional laser to improve uptake of the photosensitizer. After that a cream or gel, the so-called “photosensitizer” will be applied for 3 hours. The photosensitizing cream penetrates the skin cells, making them more sensitive to the subsequent 8-minute irradiation with cold red light. If at all, a second treatment is required after several weeks to months.
PDT is not suitable for the treatment of malignant melanoma.