Side Effects of Radiation
The goal of radiation therapy (also referred to as radiotherapy) is to
eliminate cancerous tumors within the body without destroying the surrounding
healthy tissue. This type of therapy is used in the treatment of many
cancers, even those previously considered inoperable (not treatable with
surgery), such as brain or throat cancers. New developments have led to even
more effective forms of radiation therapy, such as three-dimensional
conformal radiation therapy (3D-CRT), intensity modulated radiation therapy
(IMRT), and proton beam therapy. However, undesired side effects may
accompany even the most precise therapy. Side effects occur because within
the treatment area, radiation therapy affects any rapidly reproducing cells,
not just cancer cells, and also may shrink local blood vessels. Side effects
caused by scarring can also occur as the body heals. The medical goal of
radiation therapy is to minimize side effects while maximizing cancer cell
death. Many unwanted symptoms of radiation therapy are controlled or relieved
with medications, diet, and stretching/exercise, and
many problems disappear when treatments are completed.
Common side effects of radiation therapy
Radiation therapy, as described in PLWC
Feature: Part I: Understanding Radiation Therapy, uses directed
and invisible packets of energy to treat cancer. Radiation therapy can be
thought of as a localized, invisible, and intense “sunbeam” focused on your
cancer. Not surprisingly, a common side effect of radiation treatment is a
sunburn-type reaction in the skin through which the radiation beam passes.
Other common side effects include fatigue (tiredness) and loss of appetite.
For more information about fatigue, please read PLWC Feature: Coping
With Cancer-Related Fatigue.
For some people, radiation therapy causes little or no side effects. For
others, the side effects are more severe. The side effects of radiation
therapy vary from person to person and also with the type and location of
cancer, treatment dose, and the individual's general health.
Side effects, if experienced, often begin by the second or third week of
treatment and may last for several weeks after the final radiation treatment,
although there is significant variation depending upon the type of side
effect. Occasionally, long-term side effects occur. These include infections,
impotence (the inability to achieve or maintain an erection), infertility
(the inability to become pregnant or conceive a child), and secondary
cancers. These problems usually do not arise for months or even years after
radiation therapy, but they are more likely to be permanent and serious. Your
radiation oncologist and radiation oncology nurse specializes in radiation
therapy and will work with you to ease or prevent many of these side effects.
Misconceptions about radiation therapy
The following statements are misconceptions about radiation therapy and
comments about actual facts:
Myth: Radiation therapy is painful.
Fact: The treatments are usually short, painless, and quiet, except
for the noises from the machines.
Myth: All patients experience unpleasant reactions after radiation
Fact: Many patients have mild or no side effects. For those that do
not experience side effects, these can often be managed with the help of your
Myth: Radiation therapy causes people to "glow," and there
is a risk of exposing others to radiation.
Fact: You will not be radioactive following external-beam radiation
therapy, although certain precautions need to be followed to reduce exposure
to others if you receive internal radiation therapy (brachytherapy
or radioactive isotopes).
Myth: Radiation therapy causes baldness.
Fact: You will not lose your hair except in areas where the radiation
Myth: Radiation therapy causes infertility.
Fact: Only radiation therapy aimed at the ovaries or the testicles
carries a risk of infertility. It is recommended that you discuss the risk of
infertility associated with the treatment of your particular cancer with your
Myth: Radiation therapy causes cancers later in life.
Fact: While radiation therapy can contribute to a secondary cancer,
the risk is low. The potential benefits versus risks of treatment always must
be considered. Talk with your doctor about your individual risk.
Site-specific side effects
Head and neck
Side effects of radiation therapy to the head and neck may include mouth
sores, lack of or thickened saliva, difficulty swallowing, stiffness in the
jaw, and nausea. Your medical team can help reduce any discomfort you may
have, but only if you report what you are experiencing. Cavities in your
teeth and dryness, soreness, and infections in your mouth can be particularly
problematic; these can be lessened somewhat by taking good care of your mouth
and teeth. It is particularly important for patients receiving radiation
therapy to the head and neck to visit their dentist for a thorough oral
examination several weeks prior to treatment. This time frame allows healing
if any invasive dental procedures are necessary.
To help manage the side effects associated with head and neck radiation
therapy, avoid spicy and acidic foods; do not smoke, chew tobacco, or drink
alcohol; and brush your teeth and gums at least four times a day using
fluoride toothpaste on a soft brush. Many of these symptoms will disappear
within a month after treatments have ended, but mouth dryness may be
permanent. Artificial saliva and medication can help to ease this problem.
A particularly debilitating side effect called osteoradionecrosis
affects 3% to 10% of people with head and neck cancer. This occurs when
radiation therapy reduces blood flow to jaw bones, making them susceptible to
infections. Adequate nutrition and proper oral hygiene are necessary to avoid
or reduce the osteoradionecrosis.
Radiation therapy to the chest may cause difficulty swallowing, cough, fever,
shortness of breath, breast or nipple soreness, and shoulder stiffness, as
well as fatigue and skin irritation. A few people develop a cough, fever, and
fullness of the chest that is diagnosed as radiation pneumonitis,
an inflammation of the lung occurring between two weeks to six months after
radiation therapy. Although sometimes very mild, radiation pneumonitis may lead to permanent scarring of the lungs
called radiation fibrosis, which is associated with more serious heart and
Stomach and abdomen
Side effects from radiation therapy to the stomach and abdomen include
queasiness, nausea, or diarrhea. These symptoms will likely disappear when
treatment is completed. Your doctor can prescribe medications for these side
effects, and changes to your diet can also reduce your discomfort. For more
information, please read PLWC Feature: Managing Cancer Side Effects
Digestive problems and bladder irritation can result from radiation of the
pelvic region. Drinking fluids (not alcohol or caffeinated drinks) can help
relieve some of these issues. Again, your doctor will help you manage these
Most people who received radiation therapy of the pelvis worry about losing
sexual and reproductive abilities. Some women receiving high doses of
radiation therapy may stop menstruating and experience symptoms of menopause,
such as vaginal itching, burning, and dryness. Permanent infertility can
occur, but generally only if both ovaries receive radiation therapy. Men
receiving radiation therapy to the testes will have lowered sperm counts and
reduced sperm activity that affects fertility. Sexual performance of both men
and women can be affected, although most types of radiation therapy will not
directly impact the practice or enjoyment of sexual intercourse. Instead, the
level of desire may decrease. This can be due more to the stress of having
cancer rather than to the effects of radiotherapy. Sexual desire often
returns once treatment ends.
Of particular concern are the side effects of radiation therapy to the
prostate. The location of the prostate means that radiation treatment to this
area may affect functioning of the rectum, bladder, and penis. Side effects
may include diarrhea, rectal bleeding, incontinence, and in approximately
one-fourth to one-half of patients, an inability to obtain an erection within
a year following radiation therapy. Radiation therapy seems to gradually
decrease functioning of the nerves and blood vessels that control erection.
In particular, scarring may affect the elasticity of arteries involved in
creating an erection. Some of the radiation therapy side effects listed above
will resolve (go away) in a few weeks. Others may last a year or two after
treatment, and some, such as impotence, can be permanent. Medication and
other treatment options may be helpful. Major improvements in radiation
technology enable very precise targeting of radiation, such that treatments
result in fewer side effects. It is recommended you speak with your radiation
oncologist to minimize the occurrence and impact of these side effects. For
more information, please see the Sexuality
National Cancer Institute (NCI): Radiation Therapy and You
American Cancer Society (ACS): Radiation Therapy Effects
Head and neck cancer
NCI: Oral Complications of Chemotherapy and Head/Neck Radiation
Lung Cancer Online: Radiation Side Effects
Breastcancer.org: 5 Radiation Myths and Radiation
Prostate Cancer Foundation: Radiation
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