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Radiation therapy uses high-energy radiation (such as
x-rays)to kill cancer cells. These treatments may be given externally
in a
procedure that is much like having a diagnostic x-ray. This is called external beam radiation therapy.
Radiation therapy also may be given by placing radioactive
materials near the tumor. This is called brachytherapy.
Women treated with this type of radiation do not remain radioactive
after the implant is removed. In some situations, both brachytherapy
and external beam radiation therapy are given.
When the tumor can be seen growing through the cervix,
radiation therapy can make it easier to completely remove the cancer
with surgery. Radiation may also be given after surgery to lower the
chance of the cancer coming back in the pelvis. This, known as adjuvant
radiation, may be done for cancers that are high grade or when cancer
cells are found in the lymph nodes. In those cases, the entire pelvis
may be treated with external beam radiation therapy about 4 to 6 weeks
after surgery. Sometimes the radiation field will also include an area
of the abdomen called the para-aortic field. This is the area in the
abdomen around the aorta (the main artery).
Radiation may be done instead of surgery in a woman who
can’t have surgery because of other health problems.
External beam radiation therapy
External beam radiation therapy is the more familiar type of
treatment in which the radiation is delivered from an outside source.
This therapy requires treatment 5 days a week for 4 or 5 weeks. The
skin covering the area that is exposed to radiation is carefully marked
with permanent ink or injected dye, similar to a tattoo. A special mold
of the pelvis and lower back is custom-made to ensure that the woman is
placed in the exact same position for each treatment. The actual
external beam radiation treatment takes less than 30 minutes.
Brachytherapy
Brachytherapy places radioactive materials close to the area
to be treated (such as the tumor.
How much of the pelvis needs to be exposed to radiation
therapy depends on the extent of the disease. In cases where only the
upper third of the vagina (the vaginal cuff) needs to be treated,
radioactive material is inserted through the vagina. This is called
vaginal brachytherapy.
For this treatment, a cylinder with a source of radiation is
inserted into the vagina. With this method, the radiation mainly
affects the area in contact with the cylinder, such as the vaginal cuff
(the upper third of the vagina). Nearby structures such as the bladder
and rectum get little radiation exposure.
This procedure is done in the radiation suite of the hospital
or care center. About 4 to 6 weeks after the hysterectomy, the surgeon
or radiation oncologist inserts a special applicator into the woman's
vagina, and pellets of radioactive material are inserted into the
applicator. There are 2 types of brachytherapy: low-dose rate (LDR) and
high-dose rate (HDR).
In LDR brachytherapy, the pellets are usually left in place
for about a day at a time. The patient needs to stay immobile to keep
the pellets from moving during treatment, and so she is usually kept in
the hospital overnight. Several treatments may be necessary.
In HDR brachytherapy, the radiation is more intense. Each dose
takes a very short period of time (usually less than an hour), and the
patient can return home the same day. For uterine cancers, HDR
brachytherapy is often given weekly or even daily for at least 3 doses.
Side effects of radiation therapy
Common side effects of radiation therapy include tiredness,
upset stomach, or loose bowels. Serious fatigue, which may not occur
until a few weeks after treatment begins, is a common side effect.
Skin changes are also common, with the skin in the treated
area looking and feeling sunburned. As the radiation passes through the
skin to its intended target, it may damage the skin cells. This can
cause irritation that ranges from temporary and mild redness to
permanent discoloration. The skin may release fluid, which can lead to
infection, so care must be taken to clean and protect the area exposed
to radiation.
Diarrhea is a common side effect, but it can usually be
controlled with over-the-counter medicines. Nausea and vomiting may
also occur, but can be treated with medicines. Side effects tend to be
worse when chemotherapy is given with radiation.
Radiation can irritate the bladder and may cause problems with
urination. Bladder irritation, called radiation cystitis, can cause
discomfort and an urge to urinate frequently.
Radiation therapy may also cause scar tissue to form in the
vagina. If the scar tissue makes the vagina shorter or more narrow it
is called vaginal
stenosis. This can make vaginal intercourse painful.
A woman can help prevent this problem by stretching the walls of her
vagina several times a week. This can be done by having sexual
intercourse 3 to 4 times a week or by using a vaginal dilator (a
plastic or rubber tube used to stretch out the vagina). Still, vaginal
dryness and pain with intercourse can be long-term side effects from
radiation. Pelvic radiation can damage the ovaries, resulting in
premature menopause. This isn't an issue for most women being treated
for uterine sarcoma
this is not an issue, because they have already gone through menopause,
either naturally or as a result of surgery to treat the cancer.
As long as a woman is not bleeding heavily from a tumor in her
bladder, rectum, uterus, cervix, or vagina, she can still continue to
have sex during the course of pelvic radiation therapy. However, the
outer genitals and vagina may become sore and tender to touch, and many
women choose to stop having intercourse for a while, to let the area
heal.
Radiation can also lead to low blood counts, causing anemia
(low red blood cells) and leukopenia (low white blood cells). The blood
counts usually return to normal after radiation is stopped.
Radiation to the pelvis can impair fluid drainage from the
legs, leading to leg swelling. This is known as lymphedema and is
more common in women who had lymph nodes removed during surgery.
Pelvic radiation also can weaken the bones, leading to
fractures of the hips or pelvic bones. It is important that women who
have had pelvic radiation contact their doctor right away if they have
pelvic pain. Such pain might be caused by a fracture, recurrent cancer,
or other serious conditions.
If you are having any side effects from radiation, discuss
them with your cancer care team. There are things you can do to get
relief from these symptoms or prevent them.
Last Medical Review: 11/18/2009 Last Revised: 11/18/2009
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