Lung Cancer: Photodynamic Therapy

What is photodynamic therapy?

Photodynamic therapy (PDT) is a type of cancer treatment. For it, you get a medicine that tends to collect in cancer cells. At some point later the cells are exposed to a special light. This changes the medicine into a new form that kills the cancer cells. 

When might photodynamic therapy be used?

PDT can be used to treat lung cancer in the following ways:

  • It may be used for certain people whose lung tumors are small and near the surface of the large airways in the lung. In this case, it may cure the cancer. But only a very small number of people have their lung cancer found at such an early stage.

  • It may be used for people whose lung cancers are at a more advanced stage. It can help control some cancer symptoms. This can improve a person's quality of life. For example, if a tumor grows into an airway, it can affect a person's breathing or cause coughing or other problems. PDT can often help ease these symptoms by shrinking the tumor. PDT can also be used if a cancer comes back in an airway in a place that was treated with radiation therapy.

How is photodynamic therapy given?

You can usually get PDT as an outpatient. This means you do not have to stay in the hospital. A trained nurse or doctor injects you with the medicine porfimer sodium. You'll be sent home for 24 to 72 hours while your cells absorb the medicine. The medicine will leave most of your normal cells during this time, but it will stay longer in cancer cells and the cells of the skin.

You'll go back to the clinic or hospital for the next phase of treatment. You'll get either a numbing medicine (local anesthesia) or general anesthesia, which will make you fall asleep. Then a doctor will thread a thin, flexible, lighted tube (bronchoscope) down your throat and into your airways. This tube lets your doctor to see inside your lung. He or she will direct a special laser light right at your tumor for at least several minutes. When the doctor shines the light over the tumor, the medicine absorbs the light. It makes a form of oxygen that kills cancer cells. You can usually go home a few hours after awakening from the anesthetic.

You may need to have a "cleanup" bronchoscopy several days after PDT. This is to remove the dead cells and mucus that is too thick for you to cough up. If your doctor sees any part of the tumor still there, he or she may repeat the PDT procedure.

What are the possible side effects of photodynamic therapy?

Once you are injected with the medicine, your skin and eyes will become very sensitive to sunlight. You will be at high risk for dangerous sunburns. You need to protect your skin and eyes right away after you are injected with it. You will need to do this for at least a month to 6 weeks afterward. Your doctor or nurse will give you instructions on how to do this. You will probably need to do the following:

  • On the day of your injection, close your shades and curtains at home before you leave.

  • Bring a hat, dark sunglasses, light-colored long-sleeved shirt and light-colored long pants made out of tightly woven fabric, socks, and gloves with you to the hospital. Wear this clothing after your treatment.

  • Wear this same protective clothing every day that you go outside. This is true even on cloudy days. Do not expose your skin to sunlight for the month after treatment.

  • Avoid going outside at peak sunlight hours (10 a.m. to 4 p.m.). Limit your skin exposure at other times, even on cloudy days.

  • Sunscreen alone is not enough to protect your skin during this time.

After 30 days are up, ask your doctor if you may expose a small amount of skin on your hand to sunlight for 10 minutes. If you have swelling, redness, or blistering within the next 24 hours, you should continue to protect your skin and eyes from light for 2 more weeks. If you don't have any reaction, you may gradually increase your exposure to sunlight.

Because the activating light is focused on the tumor, the damage to your surrounding healthy tissue is usually minimal. Still, you may have burns, swelling, pain, or scarring in nearby healthy tissues near your windpipe. You may also have these temporary side effects after PDT:

  • Coughing up blood or mucus

  • Trouble swallowing

  • Stomach pain

  • Painful breathing

  • Shortness of breath

Talk with your doctor or nurse about how to ease these side effects. Ask which of these effects your doctor wants you to call about.