Radiation Oncology
Internal
Radiation Therapy: What to Expect
Your
doctor may decide that very intense radiation given to a small
area of your body is the best way to treat your cancer. Internal
radiation therapy places the source of the high-energy rays as
close as possible to the cancer cells so that fewer normal cells
are exposed to radiation. By using internal radiation therapy,
the doctor can give a higher total dose of radiation in a shorter
time than is possible with external treatment. Instead of using
a large radiation machine, the radioactive material is placed
directly into (or as close as possible to) the affected area.
Some of the radioactive substances used for internal radiation
treatment include radium, cesium, iridium, iodine, phosphorus,
and palladium.
Internal
radiation therapy often is used for cancers of the head and neck,
breast, uterus, thyroid, cervix, and prostate. Your doctor may
recommend a combination of internal and external radiation therapy.
Implant
radiation means internal radiation treatment. You also
may hear the terms interstitial radiation, intracavitary radiation,
or brachytherapy; each is a form of internal radiation therapy.
Some people use the term
"brachytherapy" whenever they are talking about any form
of internal radiation therapy.
When
interstitial radiation is given, the radiation source is placed
right in the affected tissue, usually in small tubes or containers.
These implants may be temporary or permanent. When intracavitary
radiation is used, a container of radioactive material is placed
in a cavity of the body such as the uterus. In brachytherapy,
the radioactive source, which is sealed in a small container,
is placed on the surface of the body near the tumor or a short
distance from the affected area. The radioactive source also
may be delivered to the tumor through-tubes; this is called remote
brachytherapy. Internal radiation also may be given by injecting
a solution of radioactive substance into the bloodstream or a
body cavity. When the substance is injected, it is not sealed
in a container and may be called unsealed internal radiation
therapy.
How
Is the Implant Placed in the Body?
For
most types of implants, you will need to be in the hospital and
have general or local anesthesia while the doctor places the
container for the radioactive material in your body. To
get the radiation as close as possible to the cancer, doctors
may use implants of radioactive material sealed in wires, seeds,
capsules, or needles. The type of implant and the method of placing
it depend on the size and location of the cancer. Implants may
be put right into the tumor, in special applicators inside a
body cavity, on the surface of a tumor, or in the area from which
the tumor has been taken.
Does
the Implant Spread Radiation to Others?
The
radioactive substance in your implant may transmit rays outside
your body. While you're receiving implant therapy, the hospital
may require you to stay in a private room. Although the nurses
and other people caring for you will not be able to spend a long
time in your room, they will give you all of the care you need.
You should call for a nurse when you need one, but keep in mind
that the nurse will work quickly and speak to you from the doorway
more often than from your bedside. Inmost cases, your urine and
stool will contain no radioactivity. However, either one may
contain some radioactive material if you have unsealed internal
radiation therapy.
There
also will be limits on visitors while your implant is in place.
Most hospitals do not let children younger than 18 or pregnant
women visit patients who have an implant. Visitors should sit
at least 6 feet from your bed and stay for only a short time
each day (10 to 30 minutes). Have visitors ask your nurse for
specific instructions before they enter your room.
Are
There Any Side Effects?
You
are not likely to have severe pain or feel ill during implant
therapy. However, if an applicator is holding your implant in
place, it may be somewhat uncomfortable. If you need it, the
doctor will order medicine to help you relax or to relieve pain.
Some patients feel drowsy, weak, or nauseated after having the
anesthesia to place the implant, but these effects do not last
long.
The
total amount of time that an implant is left in place depends
on the dose (amount) of radioactivity with which the patient
is treated. The implant may be low dose rate and left in place
for several days, or it may be high dose rate and removed after
a few minutes. Generally, low dose rate implants are left in
place from 1 to 7 days. Your treatment schedule will depend on
the type of cancer, where it is, your general health, and other
cancer treatments you have had. Depending on where the implant
is placed, you may have to stay in bed and lie fairly still to
keep the implant from shifting.
For
some cancer sites, the implant may be left in place permanently.
If your implant is permanent, you may need to stay in your room
away from other people in the hospital for a few days while the
radiation is most active. The implant will lose energy each day,
so by the time you are ready to go home, the radiation in your
body will be much weaker. Your doctor will advise you if there
are any special precautions you need to use at home.
High
dose rate remote brachytherapy allows a person to be treated
within a few minutes in the radiation oncology department. With
remote brachytherapy, a very powerful radioactive source travels
by remote control through tubes, or catheters, to the tumor.
The radioactivity remains at the tumor for only a few minutes.
This procedure is done by the brachytherapy team, who will watch
you on a closed-circuit television. They will talk to you through
an intercom. In some cases, several remote treatments may be
required. Sometimes, the catheter stays in place between treatments
and sometimes it is removed, depending on your condition.
High
dose rate treatments are short (usually a few minutes) and result
in less discomfort than other types of radiation therapy. Because
radioactive materials are not left in your body, you can return
home soon after you recover. Remote brachytherapy has been used
to treat cancers of the cervix, breast, lung, pancreas, prostate,
and esophagus.
What
Happens After the Implant Is Removed?
Usually
there is no need to have an anesthetic to take out the implant.
Most can be taken out right in the patient's hospital room. If
you had to stay in bed during implant therapy, you might have
to remain in the hospital an extra day or so after the implant
is removed. Once the implant is removed, there is no radioactivity
in your body. The nurses and your visitors no longer will have
to observe any special rules.
Your
doctor will tell you if you should limit your activities after
leaving the hospital. Most patients are allowed to do as much
as they feel like doing. You may need some extra sleep or rest
breaks during your first days at home, but you will feel stronger
quickly.
The
area that has been treated with an implant may be sore or sensitive
for some time after therapy. Your doctor may advise you to limit
sport and sexual activity for a while if they cause irritation
in the treatment area.
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