What is PDT?
PDT is short for Photodynamic Therapy which is a type of treatment that uses a photosensitizer– aminolevulinic acid– and a particular kind of light to treat actinic keratosis or precancerous lesions. When the photosensitizing agent is exposed to the specific wavelength of light emitted during the treatment, the agent produces oxygen that kills nearby cells. Different agents and lights are used to treat different areas of the body.
The aminolevulinic acid is applied to the body part being treated and the patient sits through a short incubation period before going into the light room. After the incubation time, the patient is introduced to the light room and the precancerous lesions are gently exfoliated away.
Moderate to severe acne can also be treated using PDT though the main use remains as a way to remove cancerous cells from the body. When combined with lasers, PDT can be even more effective when treating acne issues.
We mainly use PDT to treat actinic keratosis though PDT does have the ability to treat acne. We have seen slight effects of rejuvenation after a patient goes through PDT, though PDT will not be prescribed for skin rejuvenation.
How PDT Works
With PDT therapy, a patient’s skin is prepared with a cleaner. After that, the patient will then be treated with a slight acetone scrub to degrease the area being treated. After the area is cleansed of dirt and oils, the aminolevulinic acid is applied and patients are left to incubate. Incubation times vary:
Face: ~1 hour
Scalp: ~1.5 hours
Chest: ~2 hours
Extremities: ~3-4 hours
After the incubation time, the light therapy will last around 16 minutes– no matter the location. Once the treatment is completed, the treatment area is cleansed and a Zinc and Titanium Oxide sunscreen is applied to the area. Then, for the next 48 hours, patients are asked to have as little sun exposure as possible to gain the best results from PDT.
Why Choose PDT
There are other options for treating precancerous lesions. The most common way is with cryotherapy using liquid nitrogen. The downside of using cryotherapy is the risk of hyperpigmentation issues and scarring as a result of the treatment and only being able to treat individual lesions. The benefit to choosing PDT is less chance of scarring and pigmentation issues and you can treat a wide array of area in one treatment.
Effectiveness of PDT
The effectiveness rate for PDT treatment is around 90-99 percent when the patient has all three treatments. However, it’s highly important for the patient to receive regular check-ups to ensure the treatments were effective.