Photodynamic Therapy

Photodynamic therapy (PDT) is a cutting-edge, non-invasive treatment that targets skin cancer cells and precancerous actinic keratosis lesions caused by chronic sun exposure. Beyond treating skin cancers and pre-cancers, PDT also addresses acne, psoriasis, certain head and neck cancers, age-related macular degeneration, and premature photoaging from sun-damaged skin. Unlike radiation therapy or surgical excision, PDT requires little to no downtime and carries minimal risk of scarring, making it a preferred option for many patients who turn to board-certified dermatologist Dr. Michele Green for this innovative treatment.

PDT is a two-step process: a photosensitizing agent is first applied to the treatment area, where it is absorbed by target cells, and then a specific wavelength of light energy—such as blue, red, or laser light, or LED light—activates the drug. This activation triggers a chemical reaction that destroys target cells while sparing surrounding healthy tissue, allowing patients to resume normal activities almost immediately. In her private dermatology office in New York City, Dr. Michele Green incorporates PDT into customized treatment plans to address skin cancers, pre-cancers, sun damage, and acne.

What is Photodynamic Therapy (PDT)?

Photodynamic therapy (PDT), also called phototherapy, combines a light-sensitizing medication with a specific light source to destroy cancer cells and treat other skin conditions. The FDA first approved PDT for bladder cancer in 1993 and later for actinic keratosis (precancerous lesions) in 2004. Since then, variations of PDT have been developed to treat age-related macular degeneration, sun damage, acne, and psoriasis. Because PDT requires little downtime and does not damage DNA the way some other cancer treatments do, many patients prefer it to more invasive options. Depending on the condition being treated, you may need multiple PDT sessions to achieve optimal results. Dr. Michele Green will work with you in her private office on Manhattan’s Upper East Side to build a treatment plan tailored to your unique skin concerns.

How does photodynamic therapy work?

Photodynamic therapy requires two steps for effective treatment: applying and incubating a photosensitizing agent, then activating it with light. First, apply the photosensitizing agent topically to the affected area. Aminolevulinic acid (ALA, also known as Levulan) and porfimer sodium (Photofrin) are the two most widely used photosensitizers. Levulan treats actinic keratosis and other forms of skin cancer, whereas Photofrin is used for certain cases of lung and esophageal cancer. Levulan is activated with blue light, whereas Photofrin is activated with red light from a laser source.

Over several hours, the photosensitizing drug circulates through the body and clears from normal cells, but it remains concentrated in cancerous or precancerous cells. During this incubation period, the drug is non-toxic and does not affect surrounding tissue; it becomes active only when a specific wavelength of light is applied to the treatment area. Once activated, the drug produces singlet oxygen, a reactive form of oxygen that destroys the cells that absorbed it. Light activation can also damage the blood vessels supplying the target cells, cutting off their nutrient supply.

What photodynamic therapy is used to treat

According to the National Cancer Institute, PDT can be used to treat advanced cutaneous T-cell lymphoma, Barrett’s esophagus, esophageal cancer, and non-small cell lung cancer. It also treats nonmelanoma skin cancers, including basal cell carcinoma and stage 0 squamous cell carcinoma (Bowen’s disease), as well as precancerous actinic keratosis lesions. PDT can also relieve certain cancer symptoms, such as throat blockage from esophageal cancer and airway blockages caused by non-small cell lung cancer. Beyond oncology, PDT treats psoriasis, acne vulgaris, age-related macular degeneration, and warts.

Blue light photodynamic therapy

Blue light photodynamic therapy is a form of PDT primarily used to treat sun-damaged skin and early-stage skin cancer. Actinic keratosis lesions develop from cumulative sun exposure and typically appear as red, pink, or flesh-colored scaly patches. While these lesions are not always uncomfortable, they can be unsightly and may progress to skin cancer if left untreated. Blue light PDT uses the photosensitizing agent Levulan (ALA) and blue light to destroy lesions, which typically fade within about a week after treatment.

Photodynamic therapy for acne

Although PDT was originally approved to treat actinic keratosis and various cancers, clinical trials have shown it to be a safe and effective treatment for acne vulgaris, cystic acne, and acne scarring. PDT causes phototoxic damage to the sebaceous glands and hair follicles, shrinking the oil glands and reducing sebum production. ALA-PDT has also been shown to kill P. acnes, the bacteria responsible for many acne breakouts, making it a valuable option for patients with severe acne who have not responded to topical treatments or are ineligible for isotretinoin (Accutane).

Treatment typically begins with microdermabrasion to remove dead skin cells and enhance the penetration of the Levulan solution, which is left on the skin for 15 to 60 minutes before rinsing. The patient then sits in front of a blue light source for about 16 minutes. A series of three to five PDT sessions, spaced about four weeks apart, is typically recommended for acne, and most patients see improvement after the first treatment.

How photodynamic therapy works for skin cancer

Photodynamic therapy for skin cancers and pre-cancers follows a straightforward two-part process. The photosensitizing agent ALA (Levulan) is applied directly to the treatment area and left on for about an hour, during which precancerous and cancerous cells absorb it because they lack a normal skin barrier. The area is then exposed to blue light, which activates ALA and triggers a reaction that destroys the target cells while leaving normal skin unaffected. Treated actinic keratosis lesions typically “light up,” become redder, and disappear within several days.

If you notice new or irregular skin lesions, consult a board-certified dermatologist, such as Dr. Michele Green in NYC, who may perform a shave biopsy to confirm the diagnosis before recommending PDT. PDT is an ideal treatment for patients with numerous actinic keratosis lesions because the entire treatment area can be treated in a single session. The procedure can be performed on the face, scalp, arms, legs, and chest, and multiple treatments may be needed depending on lesion severity.

How photodynamic therapy is used to treat non-skin cancers

Photodynamic therapy is also an effective treatment for non-skin cancers, including lung and esophageal cancers. Target cells absorb a photosensitizing agent and activate it with a specific wavelength of light, destroying cancerous tissue. PDT can also damage the blood vessels that feed the tumor and alert the immune system to attack the remaining cancer cells, functioning as a localized form of immunotherapy.

Physicians typically use porfimer sodium and red laser light to treat lung or esophageal cancers. The photosensitizing agent is injected intravenously, and after an incubation period, the physician uses an endoscope to visualize the area inside the esophagus or airway and deliver laser light that activates the drug and destroys cancerous cells. Patients considering PDT for these cancers should discuss the treatment with their oncology care team.

Possible side effects of photodynamic therapy

Most PDT side effects are minor and resolve on their own within a few days after treatment. Possible side effects of photodynamic therapy include:

• Redness
• Swelling
• Peeling
• Crusting
• Burning
• Sunburn
• Temporary hyperpigmentation
• Stinging
• Blisters

After treatment, patients should avoid direct sunlight and use gentle, non-irritating skincare products to minimize irritation. In rare cases, depending on the area and type of cancer being treated, more serious side effects may occur, including:

• Cough
• Difficulty swallowing
• Shortness of breath
• Stomach pain

Following your aftercare instructions closely is essential for proper healing. If you experience any concerning side effects after PDT, contact Dr. Michele Green’s office.

Who is the ideal patient for photodynamic therapy?

Photodynamic therapy is an excellent option for patients with a history of chronic sun exposure who want to treat actinic keratosis or other pre-cancers because PDT allows an entire treatment area to be addressed at once with minimal risk of scarring, hypopigmentation, or hyperpigmentation. It is also a strong option for patients with acne vulgaris who have not responded to topical or oral antibiotics. Before treatment, patients should inform Dr. Green of any photosensitizing conditions, such as lupus erythematosus or porphyria, as well as any history of skin infections. If a patient has an active herpetic infection, such as cold sores, Dr. Green may defer treatment until the infection resolves. During your consultation at Dr. Green’s private New York City office, Dr. Green will review your medical history and skin concerns to confirm that you are an ideal candidate for PDT.

35-44-year-old man treated with photodynamic therapy to remove red spots

What is the process of Photodynamic therapy (PDT)?

If you are interested in photodynamic therapy, schedule a consultation with Dr. Green at her private Upper East Side office. She will review your medical history, skin concerns, and treatment goals, and may perform a shave biopsy of any suspicious lesions to confirm a diagnosis before scheduling your procedure. The first step of treatment involves cleansing the treatment area and applying the photosensitizing drug Levulan. The drug is allowed to air dry, then incubated on the skin for about one hour before being rinsed off completely with water.

The second step uses the BLU-U blue light device, positioned about six inches from the treatment area and activated for roughly 17 minutes to activate the Levulan. Eye shields are worn throughout the procedure to protect the eyes from the light source, and a fan can be used to keep the skin cool, since about half of patients experience stinging or burning that typically plateaus within five to six minutes. After treatment, apply SPF 50 to the treated area. Dr. Green will ask patients to send a photo of the treated area 24 hours later to confirm proper healing, and she will schedule a follow-up visit several weeks after the first session to determine whether an additional treatment is needed. Because Levulan increases the skin’s sensitivity to light, patients must avoid direct sunlight, bright indoor light, and light passing through windows for 24 to 72 hours after treatment. They should use sunglasses, a wide-brimmed hat, or protective clothing, along with broad-spectrum sunscreen of at least SPF 50, as needed.

How long does it take to recover from photodynamic therapy?

PDT is an outpatient procedure with minimal downtime, allowing patients to return home immediately after treatment. Common post-treatment effects include sunburn-like redness, itching, and swelling in the treated area. In more severe cases, blisters may develop and typically resolve within two to three days. Certain photosensitizing agents extend the window of light sensitivity — porfimer sodium, used to treat some lung and esophageal cancers, can cause light sensitivity for up to six weeks after treatment. Patients should avoid direct sunlight, bright indoor lighting, and reflective surfaces for as long as their provider recommends.

Patients should avoid saunas, steam rooms, and other heat sources, as well as exfoliating products such as retinoids or alpha hydroxy acids, for the first few days until the skin has fully healed. Dr. Green recommends applying a fragrance-free, non-comedogenic moisturizer for at least a week to support healing and cautions against picking or scrubbing the treated skin, which can lead to scarring or infection. Over-the-counter pain relievers such as acetaminophen can help with discomfort. Dr. Green will provide detailed aftercare guidance to help patients achieve and maintain the best possible results.

Frequently Asked Questions (FAQs) About Photodynamic Therapy

What is photodynamic therapy?

In dermatology, photodynamic therapy treats actinic keratosis, nonmelanoma skin cancers, acne vulgaris, and the visible signs of sun-damaged skin. Dermatologists, such as Dr. Michele Green in NYC, apply a photosensitizing agent to the skin and activate it with a specific wavelength of light to destroy targeted cells while sparing healthy tissue. This makes PDT a valuable, non-invasive option within a broader dermatologic treatment plan.

What is Levulan?

Levulan is the brand name for aminolevulinic acid (ALA), the photosensitizing agent most commonly used in photodynamic therapy for skin conditions. Apply Levulan topically to the treatment area, where precancerous and cancerous cells absorb it over roughly one hour. Once incubation is complete, blue light activates Levulan, triggering a reaction that destroys target cells while leaving surrounding healthy skin unaffected. Dr. Green uses Levulan to treat actinic keratosis, nonmelanoma skin cancer, and acne vulgaris with PDT.

What skin conditions can photodynamic therapy treat?

Photodynamic therapy can treat actinic keratosis, superficial basal cell carcinoma, acne vulgaris, and photoaging and sun-damaged skin resulting from years of cumulative UV exposure. Because PDT can treat an entire area at once, it is especially useful for patients with widespread sun damage or numerous precancerous lesions who want to avoid the downtime associated with surgery.

Does photodynamic therapy treat sun damage?

Yes. PDT is commonly used to treat sun-damaged skin and the photoaging changes that accompany it, such as rough texture and pigmented patches. Research also shows that PDT stimulates collagen production in the treated area, improving fine lines and overall skin texture while clearing precancerous lesions. Dr. Green often incorporates PDT into treatment plans for patients with a long history of sun exposure.

How effective is photodynamic therapy?

Photodynamic therapy is highly effective: the FDA has approved it to treat a variety of lung and esophageal cancers after rigorous clinical testing, and studies show it reduces cancerous cells as reliably as radiation therapy or surgery for certain cancers and pre-cancers. It also manages symptoms of several skin conditions and reduces acne breakouts by decreasing sebum production. Because PDT does not damage surrounding normal tissue, it is far less disruptive to the body than radiation therapy, and its outpatient nature allows patients to return home the same day rather than requiring hospitalization.

Does photodynamic therapy help acne?

Yes, PDT is a safe and effective treatment for patients with severe acne vulgaris, cystic acne, or acne that has not responded to topical medications. It is also a useful alternative for patients who are not candidates for isotretinoin (Accutane). Most patients see improvement after a single treatment, with continued improvement as they complete the full treatment series.

Does photodynamic therapy help wrinkles?

Emerging research suggests that PDT can help reduce fine lines and wrinkles, in addition to its primary use for cancer and pre-cancer treatment. A study of PDT published on PubMed found that treatment stimulated collagen production and improved skin texture in the treated area, suggesting that PDT may help reverse some signs of photoaging. During your consultation, Dr. Green can discuss whether PDT fits into a broader cosmetic treatment plan.

Who should not have photodynamic therapy?

PDT may not be appropriate for patients with photosensitizing conditions, such as porphyria or lupus erythematosus, because these conditions can increase sensitivity to light activation. Patients with active skin infections or herpetic outbreaks, including cold sores, should have these conditions resolved before treatment. Dr. Green will review your full medical history, including any medications that increase light sensitivity, to confirm that PDT is safe for you.

How painful is photodynamic therapy?

PDT is a non-invasive treatment, but roughly half of patients report stinging or burning during the light activation phase of the procedure. This sensation typically plateaus within five to six minutes and can be minimized with a cooling fan during treatment or a cold compress afterward.

How long does photodynamic therapy take?

A typical PDT appointment takes about 90 minutes from start to finish. The photosensitizing agent must incubate on the skin for about one hour. The treatment area is then cleaned and exposed to the light source for 16 to 17 minutes. The exact incubation and light-exposure times can vary depending on the condition being treated.

45-54 year old man treated with BLU-U light (2 weeks post treatment)

What should I expect during photodynamic therapy?

During your PDT session, the treatment area is cleansed, and the photosensitizing agent is applied and allowed to incubate for about an hour. The area is then exposed to a specific wavelength of light, such as blue light or LED light, while you wear eye shields for protection. Many patients experience temporary stinging or warmth during light activation, which subsides quickly. After the session, apply SPF 50 to the treated area.

How should I prepare for photodynamic therapy?

Before your appointment, arrive with clean, makeup-free skin and without moisturizer or sunscreen. Let Dr. Green know about any medications or skin conditions that could increase your sensitivity to light. Patients are also advised to avoid exfoliating products, such as retinoids, in the days leading up to treatment to help the skin absorb the photosensitizing agent.

What should I expect after photodynamic therapy?

After treatment, you may experience redness, swelling, and a sunburn-like sensation in the treated area for a few days. Dr. Green will ask you to send a photo of the treated skin 24 hours after your appointment to confirm proper healing. She will then schedule a follow-up visit several weeks later to assess your results and determine whether you need additional sessions.

What should I avoid after photodynamic therapy?

Because the photosensitizing agent increases your skin’s sensitivity to light for 24 to 72 hours after treatment, patients should avoid direct sunlight, bright indoor lighting, and even sitting near windows during this period. Also avoid saunas, steam rooms, strenuous exercise, and exfoliating skincare products until the skin has fully healed. Patients should avoid picking or scrubbing the treated area to prevent scarring or infection.

How much does photodynamic therapy cost?

The cost of PDT varies based on several factors, including your geographic location, the size and number of treatment areas, and the type of practice performing the procedure. Because PDT requires specialized equipment, only a limited number of dermatology practices offer it, including Dr. Green’s New York City office. During your consultation, Dr. Green can provide a personalized cost estimate tailored to your treatment plan.

Does insurance cover photodynamic therapy?

Coverage for PDT varies widely by insurance provider and by the condition being treated, so it is best to contact your insurance company, including Medicare if applicable, directly to confirm your specific benefits before scheduling treatment. Dr. Green’s office can provide documentation of medical necessity when PDT is used to treat actinic keratosis or skin cancer.

Where can I get photodynamic therapy?

Only a qualified medical professional, such as board-certified dermatologist Dr. Michele Green, should perform photodynamic therapy at a practice equipped with the specialized light devices required for PDT. Patients throughout New York City turn to Dr. Green’s private Upper East Side office for this treatment, where she customizes each PDT plan to each patient’s specific skin concerns.

Is photodynamic therapy safe?

Yes, photodynamic therapy is a safe and effective treatment for a range of cancers and skin conditions. Side effects are typically mild, such as redness, swelling, and surface irritation, and they resolve quickly after treatment. Because the procedure is non-invasive and requires no incisions, it carries a much lower risk of scarring than surgery. Unlike radiation therapy, PDT does not damage the healthy cells surrounding the treatment area.

Schedule Your Photodynamic Therapy Consultation with Dr. Michele Green Today

Photodynamic therapy is a safe, effective, and minimally invasive treatment for actinic keratosis, nonmelanoma skin cancers, acne vulgaris, sun-damaged skin, and select cancers of the lung, esophagus, and head and neck. By combining a photosensitizing agent with a targeted wavelength of light — most often blue light — PDT destroys damaged or cancerous cells while sparing surrounding healthy tissue, delivering strong results with minimal downtime. If you are ready to address precancerous lesions, stubborn acne, or the visible signs of sun damage, Dr. Michele Green will design a treatment plan tailored to your skin and goals.

Dr. Michele Green is an internationally recognized, board-certified dermatologist with over 25 years of experience providing advanced, non-invasive treatments to some of New York City’s most discerning patients. Castle Connolly, New York Magazine, Super Doctors, and The New York Times consistently name Dr. Green among NYC’s top dermatologists for her expertise and commitment to patient care. To schedule a consultation and learn whether photodynamic therapy is right for you, call the NYC-based office at 212-535-3088 or contact us online today.