What Is Photodynamic Therapy (PDT)? Everything to Know

Medically Reviewed By Megan Soliman, MD

Photodynamic therapy (PDT) is a noninvasive treatment that uses laser light and a photosensitive drug to destroy abnormal cells. PDT has many possible uses, including the treatment of certain skin conditions, such as actinic keratoses, various eye conditions Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source , and some types of cancer.

Doctors may recommend Trusted Source American Cancer Society Highly respected international organization Go to source PDT as an adjuvant treatment alongside other cancer treatments, such as chemotherapy, surgery, and radiation therapy.

As with any medical procedure, it is important to talk with a doctor about whether PDT is right for you.

This article discusses PDT in more detail, including its uses and the possible side effects.

What conditions can photodynamic therapy treat?

A person is receiving photodynamic therapy.
Patrick Lane/Getty Images

PDT has been around since the 1950s Trusted Source Wiley Peer reviewed journal Go to source . It is a treatment that uses laser light to destroy cancerous or precancerous cells or other abnormal tissue.

PDT can treat a variety Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source of conditions, including

In addition to treating these conditions, PDT helps treat bacterial, fungal, and viral infections. It may also relieve the symptoms of some cancers, such as NSCLC when it blocks the airways.

How does photodynamic therapy work?

PDT works by combining light and a drug called a photosensitizer. Examples of photosensitizers include porfimer sodium (Photofrin), which doctors deliver intravenously before the light treatment, and aminolevulinic acid (ALA or Levulan) Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source , which is a topical medication. Some oral options are also available.

The doctor will then expose your skin to a light source at specific wavelengths of 600–800 nanometers Trusted Source Wiley Peer reviewed journal Go to source . This can be anywhere from a couple of hours to a couple of days Trusted Source American Cancer Society Highly respected international organization Go to source after the delivery or application of the photosensitizer.

Doctors and dermatologists typically perform this procedure on an outpatient basis, which means that you can go home after the treatment.

How long does photodynamic therapy take?

The duration of PDT can vary. According to the United Kingdom’s National Health Service (NHS), the treatment will typically take 10–45 minutes.

The length of time can depend on the medical condition requiring treatment and how long it takes for the photosensitizer to absorb light and begin its work in the body.

Who provides photodynamic therapy?

Many healthcare professionals can provide PDT. These include dermatologists, who specialize in diagnosing, treating, and managing disorders of the skin, hair, and nails.

Other healthcare professionals who may offer PDT include plastic surgeons and some dentists Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source who provide this treatment for gum disease and other oral conditions.

What are the benefits of photodynamic therapy?

PDT has many associated benefits, including Trusted Source American Cancer Society Highly respected international organization Go to source :

  • minimal pain during and after treatment
  • low risk of scarring or infection after the site heals
  • lower cost compared with other cancer treatments
  • no need for general anesthesia
  • minimally invasive, unlike surgery or radiation therapy
  • ability to go home after the treatment instead of staying overnight in a hospital or clinic
  • limited damage to healthy cells because the photosensitizers tend to build up in abnormal cells, and the light is focused directly on them
  • better safety and lower toxicity in the treatment of malignant tumors 

Are there any side effects of photodynamic therapy?

Some side effects are possible during or after PDT. These include Trusted Source American Cancer Society Highly respected international organization Go to source :

  • discoloration or irritation in the area of exposure or the site where the doctor injected the photosensitizer
  • peeling and blisters
  • pain
  • scarring
  • itching and burning around the treated area
  • the eyes or skin becoming sensitive to sunlight and bright indoor lights for up to 6 weeks
  • the skin becoming slightly darker or lighter
  • crusting of the skin

Other side effects may occur, depending on the area undergoing treatment. These can include:

However, the side effects usually improve once the treatment is over. Let the doctor know if you have side effects so that they can help you manage them.

Are there any alternatives to photodynamic therapy?

Some factors, such as certain underlying health conditions or your overall health status, may prevent you from undergoing PDT. Your doctor will be able to recommend alternative treatments.

The treatment options can depend on the condition. Examples of treatments your doctor may recommend for cancer include:

  • Chemotherapy: This treatment uses drugs to destroy cancer cells in your body. You can receive chemotherapy topically, orally, or intravenously. Learn more about chemotherapy.
  • Radiation therapy: This treatment involves exposing the cancerous cells to high energy rays to destroy them. Your doctor may recommend radiation alone or in combination with other treatments, such as surgery or chemotherapy. Learn more about radiation therapy.
  • Surgery: Surgery involves removing Trusted Source American Cancer Society Highly respected international organization Go to source all or part of an organ that the cancerous cells affect. The surgeon may create an incision on the skin or perform laparoscopy, a minimally invasive surgical procedure.

In addition to surgery, some people may benefit from cryotherapy, which uses liquid nitrogen to freeze abnormal cells. Learn more about cryotherapy.

When should I speak with a doctor?

A doctor can provide more information if you wish to determine whether photodynamic therapy might be right for you.

If you have already undergone PDT, you should seek medical advice if any of the following apply:

  • You have trouble breathing.
  • Your skin is discolored and painful to the touch.
  • You have a fever.
  • You develop swelling or discharge around the injection site.
  • You experience heavy bleeding from the injection site.

Summary

Photodynamic therapy uses light to treat various medical conditions. It is a noninvasive treatment, so it does not require surgery or anesthesia.

PDT works by using a photosensitizer drug. Different types of photosensitizers are available in oral, intravenous, and topical forms. The doctor will then expose your skin to a specific wavelength of light.

The drug absorbs the light, which triggers a chemical reaction that releases oxygen radicals, a type of free radical that destroys the cancer cells in your body.

Common uses of PDT include treating actinic keratosis, basal cell carcinoma, and non-melanoma skin cancer. PDT also helps with inflammatory skin disorders such as psoriasis and acne.

PDT has various associated side effects, including inflammation at the injection site, discoloration, swelling, and itching. However, these should improve once the treatment is over.

If you have any concerns about PDT, it is important to contact a doctor.

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Medical Reviewer: Megan Soliman, MD
Last Review Date: 2022 Sep 14
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