Photodynamic therapy is a procedure to treat precancerous lesions and some early skin cancers. The procedure involves application of Levulan, a photosensitizing chemical, followed by exposure to a blue light source. The Levulan is applied directly to the treatment area and then allowed to incubate for approximately one to three hours. The incubation period allows the chemical time to be selectively absorbed by the abnormal or precancerous cells on the skin. The blue light then activates the chemical to destroy both visible and subclinical precancerous cells. Following the treatment, patients are instructed to avoid sun light for 36-48 hours.
Treatment of precancerous actinic keratoses is the most common application of photodyanmic therapy. Photodynamic therapy is efficient, with the treatment completed once you leave the office. It is considered a field treatment because it simultaneously treats an anatomic area (ex. entire face or scalp) versus targeting individual precancerous lesions. This means that in addition to treating the visible precancerous keratoses, it can treat the precancerous cells that are too small to be detected. For some patients, multiple treatments are recommended depending on the extent of the photodamage and response.
Photodynamic therapy can also be used to treat acne and for skin tightening procedures.