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Radiation therapy uses high-energy rays (or particles) to
destroy cancer cells. Radiation therapy is the preferred method of
treating most cancers of the vagina.
There are several ways to deliver radiation therapy. The most
common way is to carefully focus a radiation beam from a machine
outside the body. This is known as external beam radiation. External
beam radiation therapy usually involves having treatments 5 days a week
for a period of 6 weeks or so.
Another way to deliver radiation is to place radioactive
material inside the vagina. This is called intracavitary brachytherapy
or internal radiation therapy. The 2 main types of intracavitary
brachytherapy are low-dose rate and high-dose rate. For the low-dose
rate treatment, the radioactive material is inside a cylindrical
container that is placed in the vagina and stays in place for a day or
two. Although gauze packing helps hold the cylinder in place, you have
to remain in bed (in the hospital) during the treatment. With high
dose-rate intracavitary brachytherapy, the radiation source doesn't
need to stay in place for long. This allows it to be given in an
outpatient setting. Three or four treatments are given 1 or 2 weeks
apart. With these intracavitary methods, radiation mainly affects the
tissue in contact with the cylinder. This lowers the chance of bladder
and bowel side effects.
Another type of brachytherapy, called interstitial radiation,
uses radioactive material inside needles that are placed directly into
the cancer and surrounding tissues.
Side effects of radiation therapy
Radiation can destroy nearby healthy tissue along with the
cancerous cells. Side effects depend on the area being treated, the
amount of radiation, and the way that the radiation is given. Side
effects tend to be more severe for external beam radiation than for
brachytherapy.
Common radiation side effects include skin changes, fatigue,
nausea, or diarrhea. Skin changes from radiation range from mild
temporary redness to permanent discoloration. The skin may become raw
and tender. It may also release fluid, making infection more likely, so
care must be taken to clean and protect the area exposed to radiation.
Radiation to the pelvis can also cause severe irritation of
the intestines and rectum (called radiation colitis), leading to
diarrhea and bloody stool. If severe, radiation colitis can cause holes
or tears forming in the intestines (called perforations).
Pelvic radiation can also cause problems with the bladder
(radiation cystitis), leading to discomfort and an urge to urinate
often. In rare cases, radiation can cause abnormal connections to form
between the vagina and the bladder, rectum, or uterus (these are called
fistulas).
Radiation can cause the normal tissue of the vagina to become
irritated and sore. It may also cause scar tissue to form in the
vagina. The scar tissue can make the vagina shorter or more narrow
(this is called vaginal stenosis). When this happens, sex (vaginal
intercourse) can become painful. Stretching the walls of the vagina a
few times a week can help prevent this problem. One way to do this is
to have vaginal intercourse at least 3 to 4 times a week. Another
option is to use a vaginal dilator. A dilator is a plastic or rubber
tube used to stretch out the vagina. It feels much like putting in a
large tampon for a few minutes. Even if a woman is not interested in
staying sexually active, keeping her vagina normal in size allows
comfortable gynecologic exams. This is an important part of follow-up
after treatment. Vaginal estrogens may also be used to relieve dryness,
painful intercourse and help maintain the size of the vagina. Still,
vaginal dryness and pain with intercourse can be long-term side effects
from radiation. Pelvic radiation can also damage the ovaries, leading
to menopause in some women.
Radiation to the pelvis can also weaken the bones, making them
more likely to break from a fall or other trauma.
Last Medical Review: 12/30/2008
Last Revised: 05/14/2009
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