Photodynamic therapy gains favor in treating precancerous skin conditions

May 1, 2010

Nashville, Tenn. - The popularity of photodynamic therapy (PDT) for treating precancer skin conditions has increased exponentially over the past decade. The reasons are many, according to Michael Gold, M.D., medical director, Gold Skin Care Center, and clinical assistant professor, Vanderbilt University School of Medicine, department of dermatology, Nashville, Tenn.

Nashville, Tenn. - The popularity of photodynamic therapy (PDT) for treating precancer skin conditions has increased exponentially over the past decade. The reasons are many, according to Michael Gold, M.D., medical director, Gold Skin Care Center, and clinical assistant professor, Vanderbilt University School of Medicine, department of dermatology, Nashville, Tenn.

“The literature has progressively supported the effectiveness of photodynamic therapy,” he tells Dermatology Times. “For pre-skin cancers, the number of dermatologists that are using PDT is more than it was five years ago, and much more than it was even two years ago.”

PDT topicals

In the United States, there are the two main topical compounds used in conjunction with PDT for treating precancers in the skin: Levulan Photodynamic Therapy (DUSA Pharmaceuticals) and Metvixia (methyl aminolevulinate cream 16.8 percent, Galderma).

In this country, Levulan is used only as a Food and Drug Administration-indication for treating actinic keratosis (AKs) and not skin cancers. Literature has supported its effectiveness as well as the reduced recurrence rate of pre-skin cancers.

“Levulan has been in use for about 10 years, and when it first came out, the reimbursement rates for doctors were abysmal,” Dr. Gold says. “But through the work of the AAD (American Academy of Dermatology), the company, and lots of grassroots support, the reimbursement rates have become sufficient to make it a useful therapy. If you use a therapy and you lose money, you’re not going to do it.”

Metvixia, used in Europe to treat nonmelanoma skin cancers and AKs, was approved in the United States strictly for treating AKs.

“Metvixia is an incredible skin cancer drug, but for a variety of different reasons - some of which we may never know - it was not granted approval in the U.S. for treating that condition,” Dr. Gold says.

“The problem with Metvixia is that it’s a little more difficult to use and it requires a different light source,” he explains. “Its uptake here in this country over the past year, which is when it came to the U.S., has been very slow. In Europe, it’s the only drug, so it is used all the time.”

Gaining favor

Today, medical insurance covers the use of PDT for AKs, but not for skin cancers or acne. Its track record for treating pre-skin cancers is a significant contributor to its success.

Now that insurers are covering it, nearly all dermatologists are using it as one of the first treatment choices for AKs, according to Dr. Gold.

Before the boom in PDT, Levulan and Metvixia for treating pre-skin cancers, topicals like diclofenac (Solaraze, PharmaDerm) and imiquimod (Aldara, Graceway) were most popular. But while the results are good, many patients couldn’t tolerate the redness, according to Dr. Gold. And the No. 1 treatment - cryotherapy or liquid nitrogen - also has side affects, some of which can be permanent.

“A patient could end up with hypopigmentation that lasted for long periods of time,” he says. “But PDT is really user-friendly.”

You apply a medicine, let it incubate on the skin, and then apply a light. It can be blue, red or pulsed light from either a pulsed dye laser or an intense pulsed light and the AKs go away. It’s fairly simple to use for the doctors, and fairly easy for the patient. And that’s another reason why it’s caught on so well - people realize it’s not hard to do, Dr. Gold says.

Proper procedures

“I’ve been using PDT for about 10 years and I have many patients who come back and say they would rather have this treatment than anything else,” he says. “And again, there’s enough literature out there to show that it really works, and it makes the skin look good, too.

“Patients must stay out of the sun for up to 48 hours after treatment, but that is the only after-care that is really needed,” he adds. “If the procedure is done properly, the incidence of adverse events is extremely low, as shown in clinical studies.”

PDT treatments should be administered only by dermatologists, according to Dr. Gold, because “sometimes, non-dermatologists may misdiagnose conditions or not diagnose them correctly.”

Today more than ever, the literature on PDT supports both Levulan and Metvixia in the treatment of AKs. Dr. Gold believes that if dermatologists aren’t using them, they are certainly missing an opportunity.

“By now, most dermatologists know about PDT and these topicals,” he says. “It’s not hard for most people to get on board with this treatment, if they aren’t already. The companies are available to help. My belief is, if you’re not offering this to your patients, then you’re not offering the full service.”