Photodynamic therapy or PDT is a fairly new form of treatment used to treat various forms of cancer. The treatment involves utilizing various photosensitizing agents along with differing wavelengths of light to destroy the cancer cells.
In order to determine which type of PDT to utilize the type of cancer involved is primary. This is because the various light waves utilized differ in their ability to penetrate into the body. Different photosensitizing agents will also be used which are injected first into the bloodstream.
These agents will remain in the cancer cells after they are gone from the normal cells, a procedure which usually takes anywhere from 24 to 72 hours depending upon the photosensitizing agent. There are currently three PDT photosensitizing agents approved by the FDA.
Once the appropriate timeframe has passed, the wavelength of light necessary is applied and absorbed by the cancer cells. According to the National Cancer Institute, this produces an “active form of oxygen” which then will destroy the cancer cells.
It can be used just as frequently as any other form of treatment such as radiation, surgery or chemotherapy. When it comes to radiation however, PDT can be utilized repeatedly without the ultimate limitation of lifetime radiation dose.
PDT also kills cancer cells in two additional ways, it can destroy the blood vessels which supply the tumor resulting in cell death and it also stimulates the immune system which can help to destroy the cancer cells as well.
PDT can be utilized within the body to treat areas such as the lungs or esophagus with the use of an endoscope to deliver the light waves which are typically created with a laser and using fiber optic cables for the application. It can also be used to treat areas outside the body utilizing diodes (LEDs) for things such as skin cancer.
The side effects/complications of PDT are far less than those seen with other more severe types of treatment such as radiation. The NCA states “PDT can cause burns, swelling, pain, and scarring in nearby healthy tissue (3). Other side effects of PDT are related to the area that is treated.