Laser Therapy

Laser therapy for cancer treatment:

The term LASER stands for "Light Amplification by the Stimulated Emission of Radiation." Laser light is concentrated so that it makes a very powerful and precise tool. Laser therapy uses light to treat cancer cells. Consider the following additional information regarding laser therapy:

• Lasers can cut a very tiny area, less than the width of the finest thread, to remove very small cancers without damaging surrounding tissue.
• Lasers are used to apply heat to tumors in order to shrink them.
• Lasers are sometimes used with drugs that are activated by laser light to kill cancer cells.
• Lasers can bend and go through tubes to access hard to reach places.
• Lasers are used in microscopes to enable physicians to view the site being treated.

How are lasers used during cancer surgery?

Laser surgery is a type of surgery that uses special light beams instead of instruments, such as scalpels, to perform surgical procedures. There are several different types of lasers, each with characteristics that perform specific functions during surgery. Laser light can be delivered either continuously or intermittently and can be used with fiber optics to treat areas of the body that are often difficult to access. The following are some of the different types of laser used for cancer treatment:

• carbon dioxide (CO2) lasers
  Carbon dioxide (CO2) lasers can remove a very thin layer of tissue from the surface of the skin without removing deeper layers. The CO2 laser may be used to remove skin cancers and some precancerous cells.
• Neodymium:yttrium-aluminum-garnet (Nd:YAG) lasers
  Neodymium:yttrium-aluminum-garnet (Nd:YAG) lasers can penetrate deeper into tissue and can cause blood to clot quickly. The laser light can be carried through optical fibers to reach less accessible internal parts of the body. For example, the Nd:YAG laser can be used to treat throat cancer.
• laser-induced interstitial thermotherapy (LITT)
  Laser-induced interstitial thermotherapy (LITT) uses lasers to heat certain areas of the body. The lasers are directed to areas between organs (interstitial areas) that are near a tumor. The heat from the laser increases the temperature of the tumor, thereby shrinking, damaging, or destroying the cancer cells.
• argon lasers
  Argon lasers pass only through superficial layers of tissue such as skin. Photodynamic therapy (PDT) uses argon laser light to activate chemicals in the cancer cells.

What is photodynamic therapy?

Because cancer cells can be selectively destroyed while most healthy cells are spared, photodynamic therapy (PDT) is useful for the treatment of certain cancer tumors. Photodynamic therapy (also called photoradiation therapy or photochemotherapy) is a treatment that uses a combination of a light source and a photosensitizing agent (a medication that is activated by light). The photosensitizing agent collects more in cancer cells than in normal cells. When the laser's light is focused directly on the tumor, the cancer cells absorb the light, and a chemical reaction occurs which destroys the cancer cells.

The US Food and Drug Administration (FDA) has approved the use of photodynamic therapy for certain types of cancer which are found just under the skin or lining of organs, because PDT can only pass through a limited tissue depth. Cancer types that may be treated with PDT include cancer of the esophagus, non-small cell lung cancer, and actinic keratosis (a precancerous skin lesion). Advantages of PDT as shown in clinical trials are potentially fewer side effects than other treatments and the ability to use the treatment repeatedly at the same site if needed.

What cancers may be treated with laser therapy?

Lasers are used in surgery for the following types of cancer because they often have a special requirement that only lasers can meet - such as the ability to reach a hard to treat location, apply heat, or cut only a very small area:

• vocal cord
• cervical
• skin
• lung
• vaginal
• vulvar
• penile
• palliative surgery

Laser surgery is also used for palliative surgery in cancer patients. The purpose of palliative surgery is to help the patient feel better or function better even though it may not treat the cancer. An example of this type of surgery may involve surgery to remove a growth that is making it difficult for a patient to eat comfortably.

What are the side effects of photodynamic therapy?

The side effects of photodynamic therapy are relatively mild and may include a small amount of damage to healthy tissue. Also, a patient's skin and eyes are sensitive to light for as long as six weeks or more after treatment is completed. Depending on the area that is treated, patients may experience other temporary side effects. As each person's individual medical profile and diagnosis is different, so is his/her reaction to treatment. Side effects may be severe, mild, or absent. Be sure to discuss with your cancer care team any/all possible side effects of treatment before the treatment begins.

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