Photodynamic Therapy

What is Photodynamic Therapy?

Photodynamic Therapy (PDT) is a special medical treatment that uses a photosensitizing drug and a light source to activate the applied drug. This treatment is offered at Haley Dermatology & Skin Cancer Center.   The result is an activated oxygen molecule that can destroy specific cells, including pre-cancerous or certain types of cancer cells. The procedure is generally minor and performed in a physician’s office.

PDT essentially has three steps. First, a light sensitizing liquid, cream, or intravenous drug (photosensitizer) is applied or administered. Second, there is an incubation period of minutes to days. Finally, the target tissue is then exposed to a specific wavelength of light which then helps activate the photosensitizing medication.


  1. Application of photosensitizer drug
  2. Incubation period
  3. Light activation

Although first discovered around 1913, PDT in the modern sense is a fairly new, evolving science whereby varying incubation times of a light sensitizing drug are used in combination with varying types of available light sources depending on the target tissue. The basic premise of PDT is selective tissue destruction. Although the photosensitizer may be absorbed all over by many cells, atypical or cancerous cells preferentially take up more of the drug and also may retain the drug for longer duration than normal tissues.

At present, the primary limitation of available PDT techniques is the depth of penetration of the light and ability to target cells within at most 1/3 of an inch (approximately 1cm) of the light source. Therefore tumors or atypical growths must be fairly close to the skin or treatment surface for PDT to work.

What is Photodynamic Therapy used for?

Since 2001, PDT has also received many other non-FDA approved ( also called “off-label” ) uses including acne, rosacea, skin cancer, sun damage, cosmetic skin improvement, oily skin, enlarged sebaceous glands, wrinkles, rejuvenation (anti-aging), warts, hidradenitis suppurativa, psoriasis, and many other skin conditions.

Does PDT make me permanently more sensitive to light?

No, PDT causes a temporary sensitivity to light, including natural sunlight and some indoor lights. The light sensitivity resolves with time depending on both the photosensitizer drug and dosage used.

How long do I have to stay out of the sun and light?

Topically applied aminolevulinic acid (Levulan) may cause skin sensitivity only on the treatment areas for approximately 24-72 hours. These do not usually cause sensitivity on other body parts other than where the drug was directly applied.

We recommend the areas treated do not contact the sun directly or indirectly (ie. windows) for 48 hours after treatment.

How is PDT used to treat the skin?

PDT using Levulan ( 5-aminolevulinic acid or ALA ) and a proprietary Blue light is currently FDA approved for the treatment of skin pre-cancers called actinic keratosis ( rough scaly spots generally on sun exposed skin in more fair skin individuals).

PDT is also known as “ALA/PDT treatment” or “Super Blue Light”. It has been referred to as a “super photo facial” when the photosensitizer is used with a machine called intense pulsed light or IPL. Both of these devices are available at Haley Dermatology & Skin Care Center.  These treatments may help remove sun damaged pre-cancerous zones and spots. Sun damage, fine lines, and blotchy pigmentation may also be improved because of the positive effect of PDT. In some patients, PDT also has been shown to help decrease the appearance of pores and reduce oil glands, effectively treating some subtypes of patients with stubborn acne, rosacea, and help improve the appearance of some small superficial acne scars.

What is Aminolevulinic acid or Levulan?

5-aminolevulinic acid also called Levulan or ALA for short is a naturally occurring protein in the body. It is found in small quantities as part of the normal heme (blood) synthesis pathway. In larger quantities, it is a substance known to increase sensitivity to certain wavelengths of light.

How does PDT work?

By preferentially attacking the active or abnormal cells, PDT combines a very high success rate with good preservation of normal skin without significant risks for scarring. Once the areas have healed following PDT, the areas are re- examined to see if additional treatments or possible biopsies are needed.

PDT is special because it is a targeted treatment to preferentially target more rapidly dividing cells and atypical skin growths. With regular or traditional cryosurgery ( freezing with liquid nitrogen) or burning, only the visible pre skin cancers are treated thereby leaving ones that aren’t as apparent ( sub clinical or hidden) lesions undetected. Photodynamic Therapy allows for field or blanket treatment of an entire area of sun damage thereby reducing the chance that undetected pre skin cancer cells will be left untreated.

Photodynamic Therapy is scheduled in the doctor’s office because of the required photosensitizing prescription applied medication and the special light activation equipments.

What is a typical skin PDT session like?

You may be given a written procedure consent form to read and sign before your first treatment. In the treatment room, you may be sitting or comfortably lying back on a table. This part is generally painless and comfortable. Often a thorough cleansing of the area is done using acetone to degrease the skin. The less oil on the skin, the more readily the skin will absorb the applied topical medication.

The photosensitizer liquid is applied topically to the whole area being treated (such as the entire face, scalp, back of the hands, back part of the forearms, legs, feet, scalp, chest, or back).

The medication is allowed to air dry for a few minutes and then you will wait anywhere from 1-2 hours for the incubation time. Some areas such as chest, back and particularly forearms and legs require longer incubation times  for better results. No two people or skin on different areas of the body are exactly alike.

After the proper incubation time, you are brought back into the light source room where the medication is activated with a specific wavelength light source. There may be sensations of warmth, tingling, heat, or burning in some patients. Frequently, you will have a fan and cool compresses to help cool off during the treatment.

The treatment area is then washed off and sunscreen applied before leaving the office. Instructions and an appointment for follow up may then be given on how to care for the improved skin.

How much improvement can I expect?

No two individuals are the same and results may vary. As with any medical procedure, some conditions can improve dramatically in some patients and not respond in others.

Overall, patients with severe sun damaged skin manifested by actinic keratosis, texture, and tone changes including mottled pigmentation, dull or sallow skin, and skin laxity may see good to excellent improvement with PDT. There have been reports of possible improvement of large pores, non- pitted acne scars, and active acne. 

•Depending on the area being treated and the recommended incubation time, different numbers of treatment sessions spaced 4-6 weeks apart may be required to achieve the desired improvement and reduction in lesions. It is not always possible to predict ahead of time how many treatments your specific condition may take or how you will respond to PDT.

Photodynamic Therapy requires your patience and your willingness to follow the post procedure instructions, including staying out of the sun for 24-28 hours depending on the area treated and your physician’s requirements.

How long does a skin PDT procedure take?

You are generally in the medical office for several hours (average 2 hours) on the day of your Photodynamic Therapy. Facial PDT may take 10 minutes to apply the medication, 60-90 minutes to allow proper skin incubation, and 15-20 minutes for light application. Other areas may require longer incubation times and you may leave the office and come back when it is time to have the light.  It is not usually advised to have any sun exposure such as from running errands or driving around after the treatment.

Is skin PDT only for pre-cancerous growths?

No, Photodynamic Therapy is a widely used method of treating many conditions including pre-cancers (actinic keratosis), some types of superficial skin cancers, acne, rosacea, warts, sebaceous hyperplasia ( enlarged oil glands), fine wrinkles, psoriasis, and other cosmetic indications. It is currently not used to remove malignant melanoma or deeply invasive cancers. It is not used to remove moles or birthmarks.

Less frequently, Photodynamic Therapy may also be used “off-label” for other less common conditions including hidradenitis suppurativa, porokeratosis, disseminated actinic porokeratosis (DSAP), and other investigational conditions.

What are the advantages with Photodynamic Therapy for treating skin pre-cancers?

The greatest advantage of PDT is the ability to selectively treat an entire area of skin damage and pre-cancers (blanket or field treatment). PDT generally decreases the likelihood of lighter or darker skin spots ( post-inflammatory hyper or hypo pigmentation) caused by routine freezing with liquid nitrogen. Additionally, PDT frequently may facilitate smoother skin and an overall improved appearance, tone, color, and enhanced skin texture.

In several studies, PDT has been preferred by many patients for ease of use and recovery as compared to alternative treatments including freezing and chemotherapy creams like fluorouracil (Efudex). The PDT side effects may be milder with less down time than with fluorouracil.

For patients with many skin lesions, PDT may be generally more effective than repeated spot treatment with topical liquid nitrogen. Some patients are unable to tolerate the prolonged treatment required with fluorouracil (Efudex) or imiquimod (Aldara) because of the irritation, redness, and possible downtime with these topical creams.

PDT has become a very well tolerated, essentially painless, non-invasive (no needles or surgery required) procedure to help reduce sun damage and enhance the overall cosmetic outcome (particularly in sensitive areas of the face and chest).

How many treatments of Photodynamic Therapy will I need?

No two people’s skin is exactly the same and therefore individual results and number of required treatments vary. On average, most patients may benefit from 1 to 3 PDT treatments for an area and annual touch up treatments. While the face tends to respond faster and to fewer treatments, areas like the forearms and legs are much harder (resistant and tough skin) to treat and may require many more treatments.  More treatments can be done at periodic intervals in the future to maintain the rejuvenated appearance of the skin.

There is no way to reliably predict ahead of time exactly how many treatments your condition will require. Photodynamic Therapy physicians always strive to treat your condition in as few treatments as possible without causing a severe burn.

Can I remove my moles or birthmarks using Photodynamic Therapy?

No, at present Photodynamic Therapy is usually not for mole removal. Moles are usually removed by standard or traditional surgery.

Am I a good candidate for Photodynamic Therapy?

The best candidates for PDT may be those with lighter or fair skin with sun damage.

You may not be a good candidate for Photodynamic Therapy if you have darker skin that tends to turn brown or discolor with certain light or laser treatments. You may also not be a good candidate for PDT if you are very sensitive to light, burn extremely easily, would be unable to stay out of sunlight for the required 24-48 hours, or on taking medications which may make you very sensitive to sunlight or light based therapies.

Your decision on the best treatment choice may depend on different factors such as the location and type of skin lesions, your past treatments, your overall health, and level of comfort. Your physician can help you sort through the different treatments and assist in your shared decision making process. However, the right decision for you is always yours and your doctor’s to make.

What if I have other health issues?

Generally, there is not much of a problem with other health issues and PDT is safely performed in many thousands of people annually worldwide.

Your Photodynamic Therapy physician needs to know of any other medical conditions that may affect your procedure or overall wound healing. You would want to make sure to tell your physician beforehand if you have any extreme sensitivity to light based treatments, take medications which make you very sensitive to light, have had a problem or bad effect from prior PDT, have lupus, or suffer from a condition called porphyria.

Your Photodynamic Therapy physician needs to know if you have had a history of “Staph” or other skin infections in the recent past. You will want to advise your physician if you have a history of frequent cold sores ( Herpes virus infections on your face). In that case, you ay be prescribed an antiviral tablet (cold sore prevention pill) to take before and after your procedure. You may be asked to wash with a special antibiotic soap or wash like Hibiclens ( Chlorhexidine) the night or morning before your procedure to help reduce the number of bacteria on your skin.

Patients may need to also advise their physician of any drug allergies such as to topical anesthetics or other photosensitizers. Additionally, the surgeon may need to know of any bleeding or bruising tendencies, Hepatitis, HIV/ AIDS, or pregnancy.

What growths is PDT not good for?

Photodynamic Therapy is not as effective for thick skin pre-cancers called hypertrophic actinic keratosis (HAK). This may be due to the inability of the photosensitizer drug to penetrate the thick skin. These growths may need to be frozen or surgically removed or thinned using a curette prior to PDT.

PDT may also not be very useful for more advanced skin cancers like morpheaform or sclerosing basal cell carcinoma, moderately to poorly differentiated squamous cell carcinomas, recurrent tumors (tumors that were previously removed and have re-grown at the same site, or lesions in previously radiated ( x-ray or radiation treatments)sites, and malignant melanoma.

•What are alternatives for Photodynamic Therapy?

It is important to understand that as with any medical treatment, there are alternative treatments and options to PDT. You may want to discuss alternative treatment options with your doctor at your consultation appointment.

There are many options for treatment of actinic keratosis ( AK’s) including but not limited to freezing ( cryotherapy or cryosurgery), burning, chemical peels, lasers, chemotherapy creams like fluorouracil or Efudex, immune modulator creams like Aldara ( Imiquimod),  curettage and desiccation (scrape and burn), surgical removal, no treatment, and other choices depending on the skin condition.

In acne, there are many alternatives to PDT including oral Isotretinoin, oral antibiotics, topical washes, acne facials, and many acne creams.

•What about insurance coverage and costs?

Photodynamic Therapy is currently considered a medical service for the treatment of  skin pre-cancers called AK’s. However, it may be considered cosmetic, "off" label, or not medically indicated for many other conditions for which it is regularly used.

Currently, some insurance plans cover the procedure under their provided benefits. However, with the many changes in insurance plans, it is always advisable to contact your insurance carrier prior to scheduling any treatment and confirm your eligibility and benefits.

Insurance benefits vary and reimbursement depends on what benefits you have contracted for with your company. Currently, Medicare generally typically covers 80% of Photodynamic Therapy for pre cancers. If you have a secondary insurance plan, that should help take care of the remainder 20% not covered by Medicare.

Standard commercial or non-Medicare insurances currently generally may cover a large percentage of PDT for pre-cancers unless you have to meet an out of pocket deductible first. You may want to get to know and understand your insurance benefits before having surgery. In many cases, you may also ask our billing staff at Haley Dermatology or your insurance coordinator for an approximate estimate of your charges before scheduling the procedure.

How do I prepare for my procedure?

Our medical personnel will likely let you know the pre-operative instructions specific for your condition.

For a typical PDT session, most patients are advised come in with a clean, washed area without any lotions or makeup. You may generally eat your regular diet on the day of their procedure and take all of your regular daily medications.

Your skin should be fully clean and free of all make-up, moisturizers, and sunscreens. Bring a wide brimmed hat (6 inches), sunglasses, and scarf when appropriate to the appointment.

Patients are advised to wear comfortable casual clothes and bring a wide brim hat for facial or scalp treatments. You should bring gloves or a long sleeve shirt if having hands or forearms treated.

In nearly all cases, patients are usually able to drive after most procedures and do not necessarily need a driver unless they feel uncomfortable or have taken any sedative medications.

Since you will be in the office for generally at least one hour (and sometime more), you may want to bring some personal snacks, drinks, and reading or knitting material. Personal music headsets or Ipods may also provide relaxation and help pass time during your PDT application, incubation time, and treatment.

Most patients continue all doctor prescribed medications including aspirin and any blood thinners unless specifically advised otherwise only by the PDT physician.

How is recovery?

Recovery is usually fairly easy and uneventful for 95% or more of patients. Many patients have mild dryness and a faint to mild sunburn of the treated area. A small percent of patients may have moderate or marked discomfort and a harder recovery because of more skin dryness, redness, or burning.

Some of these patients have had inadvertent sun exposure even as short as a minute or two during their immediate post treatment time casing a more severe reaction. A handful of patients have reported some minor sun exposing activities like briefly stepping out to fill their yard bird feeder or walk out for a moment to grab the mail from the mailbox.  Our patients who follow the post-instructions do very well with minimal discomfort.

You will want to plan to stay indoors and avoid any sunlight for 48 hours as directed by your physician. Overall, you may be able to resume all normal indoor activities the first day.  Most patients may resume going outdoor with proper sun protection including sunscreen and hat or cover up clothing 48 hours after this treatment.

Can I return to work or school?

Most patients are able to return to work or school the 24-48 hours after Photodynamic Therapy. Avoiding direct sunlight for the first 1-2 days in crucial to avoiding getting an exuberant (red) response. Your physician will need to let you know what activity precautions are required based on the area and size of your procedure. Your skin may appear very red causing you to need to explain that you either had a PDT treatment or perhaps just say you went skiing all day and forgot to wear sunscreen.

How do I take care of my treatment area after Photodynamic Therapy?

We will give you specific wound care instructions after your procedure. You will be asked to go home and stay indoors for the rest of the day.

Keep the area cool with spray mist, cool ice packs, or aloe gel kept in the refrigerator.  Wash the skin daily with a gentle cleanser such as Cetaphil or CeraVe.  Use Biafine, a prescription that we will give you during your visit, 2-3 X daily to the areas treated to help healing.  Avoidance of harsh or abrasive cleansers are advised. Picking or scrubbing the skin could cause in severe irritation or scarring.

Your physician should be notified of any infections, cold sore outbreaks, extreme swelling, or other unexpected reactions. Rarely, a visit to the physician’s office may be necessary for severe swelling or infection. Oral antibiotics, cortisone creams or pills, or other medications may be required for adverse reactions.

Your physician will need to know if pain is increasing after 1-2 days after your procedure or if you are having fever or other concerning symptoms.  This is not a normal occurrence and should be reported immediately to our office.

What is the chance that my pre-cancers will recur?

While PDT is a very effective treatment, there is a reasonable chance that you may continue to need periodic treatments for pre cancers depending on your individual skin and severity of prior sun damage. Often there are layers of underlying sun damage from prior years that rise to the surface over time.

Photodynamic Therapy clearance rates have been reported as high as 60-90% with even one treatment. Additional treatments are advisable for patients with multiple lesions or hard to clear areas.

It is important to understand that very few treatments or surgeries have a 100% cure rate. A skin pre-cancer or cancer may recur or a new cancer may arise in the same or adjacent area even after Photodynamic Therapy or other treatments. Some skin pre- cancers are more aggressive than others and need additional treatment and closer follow up.

Good follow up appointments with your dermatologist or physician are very important, especially in the first few years after Photodynamic Therapy. Many patients are seen every 4-6 months after their diagnosis of a skin pre-cancers.

Self skin examinations monthly are good practice for patients with a history of skin cancer. Any changing or new growth should be promptly checked by your physician. More regular follow up appointments may be needed for those with more aggressive tumors or tumors in high risk areas.

Your physician will recommend the proper follow up for your specific condition.