Photodynamic Therapy for
therapy kills cancer cells using light and photosensitizing agents. These photosensitizing agents are special
drugs absorbed by the cancer cells. The drug is non-toxic. However, when the cancer cells are exposed to a
certain light, the drug activates, killing the cancer. Photodynamic therapy (PDT) is also known as phototherapy,
photoradiation therapy, and photochemotherapy.
Preparation for the
Procedure: It is important for the
patient to acclimate his/her body to the light sensitivity it will be experiencing during and after the
Photodynamic therapy treatment. The patient may cover all windows and skylights in their home as well as turn
off all lights in the house before the appointment.
Dress appropriately for the
treatment appointment. The patient should wear light colored tightly woven clothes. His/her clothes should cover
most of the body and include long sleeves, pants and socks. Gloves, dark sunglasses and a hat with a wide-brim
are also recommended to bring along.
PDT is usually
an outpatient procedure and doesn’t take long. The photosensitizing agent can be applied to the skin or injected
into the blood stream, depending on where the cancer is located. The drug is absorbed into the entire body, even
healthy cells. It takes a certain amount of time for the drugs to absorb into the cancer cells. This time period
is called drug-to-light interval
and varies anywhere from hours to days, depending on what kind of drug is used. The body eliminates much of the
drug in the healthy cells over this time.
Since the drug must be
exposed to the light in order to be effective, a laser is directed through a thin, glass, fiber optic strand to
the cancerous areas. The drug reacts with oxygen and forms a chemical which destroys cancer cells. How the fiber
optic strand is applied depends on the type of cancer. For example, when treating esophageal cancer, the fiber
optic strand is inserted into the throat through an endoscope. For lung cancer, the strand is inserted into a
bronchoscope so it can go into the lungs.
The light is not very strong
so there is little or no pain with Photodynamic therapy. The light is used on the affected area from anywhere
between 5 to 40 minutes, as necessary based on the size of the tumor. Dead tissue may be removed within a few
Types of or Techniques
Used: Photodynamic therapy is used
in a variety of ways. In addition to killing cancer directly, it is also used to destroy blood vessels feeding
the cancer. It can even be used to goad the body’s own immune system into attacking the cancer.
for Photo-dynamic treatment is highly dependent on the type of cancer being treated. The procedure is typically
painless and can even be repeated in the same site for multiple treatments and causes little or no scarring
after healing takes place. However, the patient may experience light sensitivity for up to 30 days after
Risks and Side
Effects: There are no long term side
effects of Photodynamic therapy when used properly; however, it can cause swelling and light sensitivities. The
swelling may cause pain or trouble swallowing or breathing.
It may take weeks for the
photosensitizing drugs to be completely eliminated from the body so during this time, the patient’s body may be
very sensitive to light, especially the skin and eyes. Minor sun exposure can cause burning and blistering
within minutes and eyes may be more sensitive to sunlight and different forms of light.
Though patients should
definitely avoid the sun, some indoor light exposure is necessary to help break down the drug in the patient’s
skin. After about 30 days, a doctor can test skin for signs of lingering photosensitivity from PDT.
There may be other side
effects depending on where the Photodynamic therapy treatment was administered. For example, with esophageal
cancer the patient may experience nausea, vomiting, high temperature, headache, hiccups or dehydration. Lung
cancer treatments may cause blood in the phlegm, pneumonia, bronchitis or trouble breathing.
Always ask your doctor what
may be expected with your personal Photodynamic therapy treatment.