What is Photodynamic Therapy?
Photodynamic therapy (PDT) is considered a targeted anticancer treatment — one that kills tumor cells without permanently damaging surrounding tissue. Developed and pioneered at Roswell Park by Thomas Dougherty, PhD, in the late 1970s, today PDT is used worldwide in the treatment of many cancer types, including skin, lung, breast, esophagus, pleura, head and neck, mouth, larynx and GYN cancers.
PDT is a two-step treatment that uses a light sensitive drug and non-thermal visible red light (from a laser or other light source) to destroy the cancer cells in solid tumors.
How Does Photodynamic Therapy Work?
A non-toxic drug called Photofrin® (porfimer sodium) is injected intravenously, and is absorbed by your body’s cells. After two to three days, however, the drug clears from normal body cells, but remains concentrated in malignant ones.
When the laser’s non-thermal red light is focused on the tumor (through a bronchoscope or during surgery) the light activates the drug, causing an almost immediate destruction of the tumor cells.
Because Photofrin® is also retained by skin, patients are required to avoid direct sunlight, very bright artificial lights, and cone- or helmet-type hairdryers for about 4 to 6 weeks after injection. Patient must also protect themselves with sunglasses, dark-colored clothing, long-sleeved shirts, hat, gloves and long pants when outdoors.
Newer Photosensitizer Drugs
Roswell Park is currently evaluating 2nd generation photosensitizers in clinical trials. Photochlor® (commonly called HPPH) is one such drug, and offer the benefit of a far shorter duration, just 7 to 14 days, of the light-sensitivity side effect.
Using PDT During Surgery
Because the laser light must reach the tumor directly, PDT has been limited to treating lung tumors only in areas that can be accessed by a bronchoscope. Roswell Park physicians are pioneering a new approach — using PDT during surgery — allowing more patients to benefit from PDT and improve their outcome.
Learn more about our latest research and how PDT may help your cancer at the Photodynamic Therapy Center.