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What is internal radiation therapy?
Your doctor may recommend internal radiation therapy (also
called brachytherapy) as the best way to treat your cancer. Instead of
using radiation beams aimed from a large machine, the radiation source
is usually sealed in a small holder (called an implant). The implant is
placed very close to or inside the tumor. The material is placed so
that it harms as few of the normal cells as possible. The material
itself may be left in the body for only a short time, or it may be left
there permanently. This allows the doctor to give a high dose of
radiation to a smaller area than is possible with external radiation
treatment.
The main types of brachytherapy are intracavitary
radiation and interstitial
radiation. Both of these methods involve using radioactive implants,
such as metal pellets, seeds, ribbons, wires, needles, capsules, or
tubes. During intracavitary radiation, the material is placed in a
cavity (space) in the body, such as the uterus. With interstitial
radiation, the implants are placed in or near the cancer, but not in a
body cavity.
How are implants placed in the body?
Sealed radioactive substances are placed in body cavities or
body tissue with applicators,
which are often metal tubes or plastic tubes called catheters. This is
done in a hospital operating room. You will get anesthesia, which may
be either general (where you are given drugs to put you into a deep
sleep) or local (where part of your body is numbed). The applicators
are put in by a doctor using an imaging test (such as an x-ray or MRI)
to look at the exact area where the radiation needs to go. If the
applicators need to stay in, stitches may be used to keep them in place
until treatment is over.
During the actual radiation treatment, the implants are put
into the body through the applicator(s). Some implants are permanent.
They are put in through the applicator and then the applicator is
removed. Other implants are left in only for a certain amount of time.
For the implants that will be removed after a certain number of
minutes, hours, or days, the applicator is usually left in until the
treatment is finished. The applicator is then removed when the implants
are taken out for the last time.
How long do implants stay in place?
The type of implant you receive and your treatment schedule
will depend on the type of cancer, where it is in your body, your
general health, and other treatments you have had. Some implants
deliver low doses of radiation. They are left in place for many days or
may even be permanent. Others deliver high doses of radiation and are
taken out after only a few minutes.
Some low-dose implants are left in place from 1 to 7 days. For
larger implants, depending on where the implant is placed, you may have
to stay in a hospital bed and lie fairly still to keep it from moving.
Some smaller implants (such as the seeds or pellets used to
treat prostate cancer, and some lung cancers) may be left in
permanently. Over the course of several weeks they stop giving off
radiation. The seeds are about the size of rice grains and rarely cause
problems. If your implants are to be left in, you may be able to go
home the same day they are put in (or the day after). But you will need
to stay in the treatment center until the anesthesia wears off.
Sometimes special precautions are needed to protect family and friends
from the radiation given off by the implants. Ask your health care team
about this.
High-dose-rate
(HDR) brachytherapy allows a person to be treated for only
a few minutes at a time with a powerful radioactive source that is put
in the applicator. The source is removed after only a few minutes. This
may be repeated over the course of a few days to weeks. The radioactive
material is not left in your body. Sometimes the applicator is left in
place between treatments, or it may be put in place before each
treatment.
How will I feel during implant therapy?
You are not likely to have a lot of pain or feel sick while
implants are being put in. The anesthesia used while they are being
placed might make you feel drowsy, weak, or nauseated, but these side
effects do not last long. If your implant is held in place by an
applicator, you may have some discomfort in that area. Ask for medicine
to help you relax or to relieve pain if needed. Be sure to tell the
nurse if you have any burning, sweating, or other symptoms.
What happens after a temporary implant is
removed?
In most cases, anesthesia is not needed when the applicator
and/or implant is removed. It is usually done right in your hospital
room. The treated area may be sore or tender for some time after
treatment, but most patients can return to normal activities quickly.
Keep in mind that your body is recovering, and you may need extra sleep
or rest breaks over the next few days.
What happens to permanent implants?
Radioactive material will stop giving off radiation over time.
This may take weeks or months. Talk to the doctor or nurse about how
long this may take in your case. Once the radiation is gone, the
implant(s) are no longer active. Usually they stay in place and cause
no harm, and they do not need to be removed.
Will I be radioactive during or after
internal radiation treatment?
With internal radiation therapy, your body may give off a
small amount of radiation for a short time. If the radiation is
contained in a temporary implant, you will be asked to stay in the
hospital and may have to limit visitors during treatment. You also may
be asked to stay a certain distance away from them. Pregnant women and
children may not be allowed to visit you. With sealed implants, body
fluids and materials used by the patient are not radioactive.
Permanent implants give off small doses of radiation over a
few weeks to months as they slowly stop giving off radiation. The
radiation usually doesn’t travel much farther than the area
being treated, so the chances that others could be exposed to radiation
is very small. Still, your health care team may ask you to take certain
precautions such as staying away from small children and pregnant
women, especially just after you get the implants.
Last Medical Review: 12/23/2008
Last Revised: 12/23/2008
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