What Happens During Photodynamic Therapy (PDT) for Esophageal Cancer
Photodynamic therapy (PDT) is a type of laser treatment. It is a two-step process.
Step 1: Injection of a photosensitizing agent
You go to the hospital or a clinic to have a nurse or doctor inject you with a drug called Photofrin (porfimer sodium). You’ll be sent home for 24 to 72 hours while your cells absorb the drug. The drug will leave most of your normal cells during this time, but it will stay longer in cancer cells and your skin cells.
Step 2: PDT procedure with laser
You’ll go back to the clinic or hospital for the next phase of treatment. You’ll get either sedation with a local anesthesia (numbing medicine) or general anesthesia, which will make you fall asleep and not feel pain.
Then, a doctor will thread a thin and flexible, lighted tube called an endoscope through your esophagus so that he or she can see inside. Your doctor also uses the endoscope to direct a special wavelength of laser light directly at the cancer. For this reason, PDT can only be used on cancers near the inner surface of the esophagus, where they can be reached by the endoscope.
Photofrin is a photosensitizing agent, which means that it reacts to a specific wavelength of light. When the doctor shines the special laser light over the cancer cells, they absorb the light and make a form of oxygen that kills cancer cells. The doctor directs the light at the tumor for 5 to 40 minutes depending on its size.
You can usually go home a few hours after the procedure.
Any dead areas of cells left in the treated area might need to be removed a few days later using endoscopy. The PDT treatment can be repeated if needed.