Photodynamic therapy

Photodynamic therapy (PDT), also known as photodynamic light therapy, is a laser light-based therapy used to treat certain types of cancer and some noncancerous conditions. It’s a noninvasive treatment that combines the use of photosensitizing medication with a narrow beam of laser light. When treated cells are exposed to laser light, the photosensitizing agent in the medication absorbs the light and produces an active form of oxygen that destroys cancerous tissues.

PDT medications are absorbed throughout the body, but the photosensitizing agent remains in cancer cells longer than it does in normal cells. The light exposure is timed carefully so it occurs when most of the photosensitizing agent has left healthy cells but is still present in cancer cells. As a result, photodynamic therapy causes minimal damage to healthy tissue.

The radiation oncology and cancer care team members at Penn Medicine are experts in delivering cancer therapies, including specialized treatments like photodynamic light therapy. You’ll have access to a multidisciplinary team, including a radiation oncology doctor, nurses, therapists, and other providers with experience in providing photodynamic therapy. We can answer any questions you have about your treatment so you can be confident in your treatment plan and in our ability to support the best possible outcome.

Photodynamic therapy for cancer is mainly used for tumors where laser light can reach. It’s often used to treat cancer on or just under the skin or on the lining of internal organs that can be reached by delivering laser light through a thin fiber optic tube.

PDT results in less scarring of tissue and can be used for repeated treatments on the same site, making it a preferred treatment for certain types of cancer or other conditions. Your doctor may recommend photodynamic light therapy in cases where scarring or repeated treatments are a consideration.

Currently, photodynamic therapy for cancer is used at Penn Medicine to treat:

• Skin cancer
• Gastrointestinal cancer such as stomach cancer and gastrointestinal stromal tumors 
• Lung cancer

Your doctor will talk with you about whether PDT is right for you.

Your doctor will set a schedule that includes your number of treatments and overall timeline. Generally, you’ll be at Penn Medicine for about an hour every day for each treatment session. Photodynamic therapy can run five days a week for several weeks.

To prepare for your treatment, you’ll receive photosensitizing medication, either by injection into the bloodstream or as a pill. You’ll wait for the medication to settle in the cancerous cells, where it collects. Your doctor will advise you on how long you’ll need to wait before the laser light treatment can begin.

Once the medication settles, your provider will focus a narrow beam of light on the treated cells. The light can be directed through a fiber-optic tube (a very thin glass strand) that’s placed close to the cancer to deliver the proper amount of light. Additional delivery methods may be needed depending on the location of the cancer. For example, the fiber-optic tube may be directed through a bronchoscope into the lungs for treatment of lung cancer.

At the start of each session, a therapist will spend five to 15 minutes positioning you for treatment and setting up the equipment as instructed by your doctor. X-rays may be taken to be sure you’re in the proper treatment position. There’s no pain during the procedure. Though if you have physical limitations, you may experience some discomfort when positioned for the session.

You’ll be seen regularly by your radiation oncologist throughout treatment to evaluate your response to photodynamic therapy. Blood tests and x-rays may be ordered to monitor progress. If the tumor shrinks significantly during treatment, your doctor may update your treatment plan to focus more precisely on the remaining cancer cells and spare healthy tissue.

Your skin and eyes may be more sensitive to light after photodynamic therapy. This is usually a short-term side effect that resolves within a few months after your treatment is completed. Other possible side effects at the treatment site may include:

• Swelling
• Burning, itching, or stinging sensations
• Infection

Additional side effects may be related to the type of cancer being treated. For example, if you are being treated for lung cancer, you may experience shortness of breath or coughing. Talk with your doctor about possible side effects related to your specific case.

Because Penn Medicine was the first to use PDT in the southeastern Pennsylvania and New Jersey regions, our radiation oncologists and providers have extensive experience using light-sensitive medication together with low-level beams of light to eliminate cancer cells. They’ll consult with you about the best approaches for your care—whether it’s PDT or another form of radiation therapy.

You can expect the highest level of care for your cancer treatment at Penn Medicine:

• Radiation treatment that’s right for you with doctors dedicated to treating your type of cancer
• Time-tested radiation therapies alongside the latest technologies to offer the best possible outcomes based on research-based approaches
• The highest safety and care standards in nationally accredited facilities that provide an exemplary level of care
• An entire team dedicated to your care with doctors, therapists, nurses, and other providers who specialize in radiation treatment