Photodynamic therapy, or PDT, is a three-step treatment used to treat mild or serious conditions of the skin through the use of a photo-sensitizing medication and a light source to activate it. PDT destroys abnormal cells that cause actinic keratosis, a precancerous condition or to treat certain forms of skin cancer. It may also be used to minimize pores and reduce oil glands in order to treat acne and rosacea, and is sometimes helpful in minimizing the appearance of scar tissue as well.
In addition to destroying precancerous cells by forcing their interaction with oxygen, there is evidence that photodynamic therapy is able to damage the blood vessels within tumors and to activate the patient's immune system to attack malignant cells. Several photodynamic therapy treatments may be required and this variety of therapy may be used alone or in combination with other treatments for cancer, such as surgery, radiation therapy or chemotherapy.
During a PDT treatment, a topical photo sensitizer called Levulan is either administered by injection or applied topically to the skin and left on for a period lasting from one to several days. Levulan is made of aminolevulinic acid, or ALA, a natural substance found in the body. After absorption, the Levulan is activated with a wavelength light source targeting the affected tissue. Patients may experience sensations of warmth, tingling, heat or burning during this part of the treatment. After light activation, the treated area is washed and patients can return home, and most return to work within one to two days after the procedure.
For optimal results, patients may need up to five treatment sessions, depending on the nature and severity of their condition. Sessions are spaced 2 to 5 weeks apart, and can be continued afterwards to help maintain the initial positive results of treatment.
Although PDT is considered a safe treatment option, there are side effects associated with any medical procedure. Some of most common side effects of photodynamic therapy are localized redness, hyperpigmentation, bruising, infection and scarring. These side effects are usually mild and resolve on their own within a few weeks.