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The word LASER stands for Light Amplification by Stimulated Emission of Radiation.
Laser light is different from regular light. The light from the sun or from a light bulb has many different wavelengths and spreads out in all directions. Laser light, on the other hand, has a single, high energy wavelength and can be focused in a very narrow beam. This makes it both powerful and precise.
Lasers can be used instead of blades (scalpels) for very careful surgical work, such as repairing a damaged retina in the eye or cutting body tissue. They can also be used to heat and destroy small areas (such as some tumors), or to activate light-sensitive drugs.
Lasers are named for the liquid, gas, solid, or electronic substance that is used to create the light. Many types of lasers are used to treat medical problems, and new ones are being tested all the time. The main types of lasers currently being used in cancer treatment include:
Doctors and other health professionals who use these lasers need special training in how to operate and safely handle them.
The CO2 laser can cut or vaporize (dissolve) tissue with fairly little bleeding. It does very little damage to the surrounding or deep tissue. This type of laser is sometimes used to treat pre-cancers and some early-stage cancers.
The argon laser, like the CO2 laser, only goes a short distance into tissue. It is useful in treating skin problems and in treating some types of eye tumors. It’s sometimes used during colonoscopies (tests to look for colon cancer) to remove polyps before they become cancer. It also can be used with light-sensitive drugs to kill cancer cells in a treatment known as photodynamic therapy (PDT). Another way it can be used is to help stop bleeding by sealing blood vessels in patients who are getting radiation therapy for certain types of cancer. This might be needed in some cases because radiation therapy can damage the blood vessels near the tumor, causing them to tear and bleed.
Light from this laser can go deeper into tissue than light from other types of lasers, and it can make blood clot quickly. Nd:YAG lasers can be used through thin flexible tubes called endoscopes to get to hard-to-reach parts inside the body, such as the esophagus (swallowing tube) or the large intestine (colon). This light can also travel through flexible optical fibers (thin, clear tubes) that are put into a tumor, where the light's heat can destroy it.
Lasers can be used in 2 main ways to treat cancer:
Though lasers can be used alone, they are often used with other cancer treatments, such as chemotherapy or radiation therapy.
The CO2 and Nd:YAG lasers are used to shrink or destroy tumors. They can be used with thin, flexible tubes called endoscopes that let doctors see and work inside certain parts of the body that could not otherwise be reached except by major surgery. Using an endoscope also helps position the laser beam to accurately hit its target.
Lasers are used this way to treat many kinds of cancer. Here are some examples:
For most types of photodynamic therapy (PDT), a special drug called a photosensitizing agent is put into the bloodstream. Over time it is absorbed by body tissues. The drug stays in cancer cells for a longer time than in normal cells.
Photosensitizing agents are turned on or activated by certain types of light. For example, an argon laser can be used in PDT. When cancer cells that contain the photosensitizing agent are exposed to light from this laser, it causes a chemical reaction that kills the cancer cells. Light exposure must be carefully timed so that it’s used when most of the agent has left healthy cells, but is still in the cancer cells.
PDT is sometimes used to treat cancers and pre-cancers of the esophagus (swallowing tube), bile duct, bladder, and certain kinds of lung cancer that can be reached with endoscopes.
PDT is also being looked at for use in other cancers, such as those of the brain, pancreas, and prostate. Researchers also are looking at different kinds of lasers and new photosensitizer drugs that might work even better.
To learn more about PDT, see Photodynamic Therapy.
Lasers are also being looked at to treat or prevent side effects of common cancer treatments. For instance, low-level laser therapy (LLLT) might be helpful in treating the arm swelling (lymphedema) that can result from breast surgery. Lymphedema in the arm is a risk when lymph nodes in the armpit are removed during surgery. Some studies are also looking at LLLT for preventing or treating severe mouth sores caused by chemotherapy.
Lasers have some benefits and drawbacks compared with standard surgical tools. Each person’s case is different, so it’s important to discuss the pros and cons of laser therapy with your doctor to decide if it might be right for you.
Lasers have some advantages (pros) and disadvantages (cons) compared with standard surgical tools.
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
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Last Revised: May 4, 2020
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