- Key points in laser cancer
treatment
o Laser light is a light of such high
intensity and narrow beam that it can be used to do precise surgery to
remove cancer or precancerous growths or to relieve symptoms of cancer. It
is used most often to treat cancers on the surface of the body or the
lining of internal organs.
o Laser therapy is often given through
a thin tube called an endoscope. An endoscope can be inserted in openings
in the body to treat cancer or precancerous growths inside the trachea
(windpipe), esophagus, stomach, or colon.
o Laser therapy causes less bleeding
and damage to normal tissue than standard surgical tools, and there is a
lower risk of infection.
o However, laser therapy is extremely
expensive and the effects of the surgery may not be permanent, so the
surgery may have to be repeated.
What is laser light?
The term “laser” stands for light amplification by stimulated emission of
radiation. Ordinary light, such as that from a light bulb, has many
wavelengths and spreads in all directions. Laser light, on the other hand,
has a specific wavelength. It is focused in a narrow beam and creates a
very high-intensity light. This powerful beam of light may be used to cut
through steel or to shape diamonds. Because lasers can focus very
accurately on tiny areas, they can also be used for very precise surgical
work or for cutting through tissue (in place of a scalpel).
What is laser therapy, and how is it used in
cancer treatment?
Laser therapy uses high-intensity light to treat cancer and other
illnesses. Lasers can be used to shrink or destroy tumors. Lasers are most
commonly used to treat superficial cancers (cancers on the surface of the
body or the lining of internal organs) such as basal cell skin cancer and
the very early stages of some cancers, such as cervical, penile, vaginal,
vulvar, and non-small cell lung cancer.
Lasers also may be used to relieve certain symptoms of cancer, such as
bleeding or obstruction. For example, lasers can be used to shrink or
destroy a tumor that is blocking a patient’s trachea (windpipe) or
esophagus. Lasers also can be used to remove colon polyps or tumors that
are blocking the colon or stomach.
Laser therapy can be used alone, but most often it is combined with other
treatments, such as surgery, chemotherapy, or radiation therapy. In
addition, lasers can seal nerve endings to reduce pain after surgery and
seal lymph vessels to reduce swelling and limit the spread of tumor cells.
How is laser therapy given to the patient?
Laser therapy is often given through a flexible endoscope (a thin, lighted
tube used to look at tissues inside the body). The endoscope is fitted
with optical fibers (thin fibers that transmit light). It is inserted
through an opening in the body, such as the mouth, nose, anus, or vagina.
Laser light is then precisely aimed to cut or destroy a tumor.
Laser-induced interstitial thermotherapy (LITT) (or interstitial
laser photocoagulation) also uses lasers to treat some cancers. LITT is
similar to a cancer treatment called hyperthermia, which uses heat to
shrink tumors by damaging or killing cancer cells.During LITT, an optical
fiber is inserted into a tumor. Laser light at the tip of the fiber raises
the temperature of the tumor cells and damages or destroys them. LITT is
sometimes used to shrink tumors in the liver.
Photodynamic therapy (PDT) is another type of cancer treatment that
uses lasers. In PDT, a certain drug, called a photosensitizer or
photosensitizing agent, is injected into a patient and absorbed by cells
all over the patient’s body. After a couple of days, the agent is found
mostly in cancer cells. Laser light is then used to activate the agent and
destroy cancer cells. Because the photosensitizer makes the skin and eyes
sensitive to light for approximately 6 weeks, patients are advised to
avoid direct sunlight and bright indoor light during that time.
What types of lasers are used in cancer
treatment?
Three types of lasers are used to treat cancer: - o Carbon
dioxide (CO2) lasers
- o
Argon lasers
- o
(Nd:YAG) lasers (neodymium:yttrium-aluminum-garnet)
-
- Each of these can shrink or destroy tumors and can
be used with endoscopes. CO2 and argon lasers can cut the skin’s surface
without going into deeper layers. Thus, they can be used to remove
superficial cancers, such as skin cancer. In contrast, the Nd:YAG laser is
more commonly applied through an endoscope to treat internal organs, such
as the uterus, esophagus, and colon. Nd:YAG laser light can also travel
through optical fibers into specific areas of the body during LITT. Argon
lasers are often used to activate the drugs used in PDT.
What are the advantages of laser therapy?
Lasers are more precise than standard surgical tools (scalpels), so they
do less damage to normal tissues. As a result, patients usually have less
pain, bleeding, swelling, and scarring. With laser therapy, operations are
usually shorter. In fact, laser therapy can often be done on an outpatient
basis. It takes less time for patients to heal after laser surgery, and
they are less likely to get infections. Patients should consult with their
health care provider about whether laser therapy is appropriate for them.
What are the disadvantages of laser therapy?
Laser therapy also has several limitations. Surgeons must have specialized
training before they can do laser therapy, and strict safety precautions
must be followed. Also, laser therapy is expensive and requires bulky
equipment. In addition, the effects of laser therapy may not last long, so
doctors may have to repeat the treatment for a patient to get the full
benefit.
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