Photodynamic therapy (PDT) uses a combination of light energy and photosensitizing medications to treat certain types of cancer and other health conditions such as psoriasis, acne and infections.
Photodynamic therapy (PDT) destroys harmful cells, including cancer cells, using drugs called photosensitizers. Light activates these drugs and creates a chemical reaction that destroys the harmful cells.
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Healthcare providers use PDT to treat a wide range of medical issues, including skin conditions, many types of cancer and some noncancerous conditions.
Healthcare providers may recommend photodynamic therapy for:
PDT is also used to treat many different types of cancer. Your healthcare provider may recommend photodynamic therapy for:
In some cases, PDT can treat noncancerous conditions, such as:
During treatment, your healthcare provider gives you a photosensitizer. Depending on where the target area is located in your body, this medication might be given in pill form, through your vein (intravenously) or applied directly to your skin. The photosensitizing drugs concentrate in cancer cells and other unhealthy cells to make those cells more sensitive to light.
After administering the photosensitizer, your healthcare provider shines a special light on the treatment area. Depending on the type of photosensitizer used, your healthcare provider may use low-power red laser light, blue light or natural sunlight. If the treatment area is in your throat, airways or lungs, your healthcare provider will use an endoscope (a thin, flexible tube) to shine light on the cells inside of your body. Under the light, the photosensitizing agent reacts with oxygen, causing a chemical reaction that destroys unhealthy cells.
You may receive repeat phototherapy treatments as needed. Your healthcare provider will determine if and when you receive further PDT.
In most cases, PDT treatment sessions take anywhere from 15 to 90 minutes. Treatment time depends on the size of the targeted area.
It depends on your unique situation. All the cells in your body absorb the photosensitizing agent, but these drugs stay longer in abnormal cells than in healthy cells. Some photosensitizing agents start collecting in unhealthy cells immediately. Others take hours or days to build up in large enough amounts for effective treatment. Your treatment timeline, including how many treatments you receive and how often you receive them, depends on the photosensitizing agent your healthcare provider prescribes.
PDT offers many benefits compared to other medical treatments:
Like any medical procedure, PDT carries the risk of side effects. Photosensitizing agents affect both unhealthy and healthy cells, making you more sensitive to light even after your treatment is complete. Your skin and eyes may be more sensitive to light for as long as three months after your procedure.
Other possible side effects of PDT include:
If you have PDT to your esophagus, your side effects may include:
Risks of PDT for people living with non-small cell lung cancer include:
Photodynamic therapy can only treat areas of your body where light can reach. It’s effective when treating skin problems or the lining of organs that can be reached with a light source. But it can’t treat large cancers or cancers that have grown deep into your skin.
It usually takes about two to six weeks to fully heal after PDT, depending on the area of your body that’s being treated.
Most people return to their daily activities immediately following PDT. Some people need to take extra steps to protect their skin and help the treatment area heal.
Your healthcare provider may recommend covering the treatment area to help protect your skin. You may need to make lifestyle changes for short periods of time, depending on the photosensitizer your healthcare provider uses. These lifestyle changes may include:
When treating skin conditions, PDT results are usually semi-permanent, lasting several months. When treating cancer, research shows that PDT can be just as successful as chemotherapy or radiation in certain cases. Whether you need repeat sessions depends on several factors, including the type of cancer you have, where it’s located and how well you respond to treatment.
If you’re diagnosed with skin cancer or another medical condition that may benefit from PDT, ask your healthcare provider if this treatment could be a good option for you.
A note from Cleveland Clinic
Photodynamic therapy can treat a number of health conditions, including many types of cancer. It minimizes damage to healthy cells, has no known long-term side effects and can often be performed as an outpatient procedure. To find out of photodynamic therapy is right for you, schedule an appointment with your healthcare provider.
Last reviewed by a Cleveland Clinic medical professional on 04/25/2022.
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