Internal Radiation Therapy Used?
Your doctor may decide that a high dose of
radiation given to a small area of your body is
the best way to treat your cancer. Internal
radiation therapy allows the doctor to give a
higher total dose of radiation in a shorter time
than is possible with external treatment.
Internal radiation therapy places the radiation
source as close as possible to the cancer cells.
Instead of using a large radiation machine, the
radioactive material, sealed in a thin wire,
catheter, or tube (implant), is placed directly
into the affected tissue. This method of treatment
concentrates the radiation on the cancer cells and
lessens radiation damage to some of the normal
tissue near the cancer. Some of the radioactive
substances used for internal radiation treatment
include cesium, iridium, iodine, phosphorus, and
Internal radiation therapy may be used for cancers
of the head and neck, breast, uterus, thyroid,
cervix, and prostate. Your doctor may suggest
using both internal and external radiation
In this booklet, 'internal radiation treatment'
refers to implant radiation. Health professionals
prefer to use the term "brachytherapy" for implant
radiation therapy. You may hear your doctor or
nurse use the terms, interstitial radiation
or intracavitary radiation; each is a form
of internal radiation therapy. Sometimes
radioactive implants are called "capsules" or
How Is the Implant Placed in the Body?
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
(interstitial radiation), in special applicators
inside a body cavity (intracavitary radiation) or
passage (intraluminal radiation), on the surface
of a tumor, or in the area from which the tumor
has been removed. Implants may be removed after a
short time or left in place permanently. If they
are to be left in place, the radioactive substance
used will lose radiation quickly and become
non-radioactive in a short time.
When interstitial radiation is given, the
radiation source is placed in the tumor in
atheters, seeds, or capsules. When intracavitary
radiation is used, a container or applicator of
radioactive material is placed in a body cavity
such as the uterus. In surface brachytherapy the
radioactive source is sealed in a small holder and
placed in or against the tumor. In intraluminal
brachytherapy the radioactive source is placed in
a body lumen or tube, such as the bronchus
Internal radiation also may be given by injecting
a solution of radioactive substance into the
bloodstream or a body cavity. This form of
radiation therapy may be called unsealed
internal radiation therapy.
For most types of implants, you will need to be in
the hospital. You will be given general or local
anesthesia so that you will not feel any
pain when the doctor places the holder for the
radioactive material in your body. In many
hospitals, the radioactive material is placed in
its holder or applicator after you return to your
room so that other patients, staff, and visitors
are not exposed to radiation.
Are Other People Protected From Radiation While
the Implant is in Place?
Sometimes the radiation source in your implant
sends its high energy rays outside your body. To
protect others while you are having implant
therapy, the hospital will have you 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. In most cases,
your urine and stool will contain no radioactivity
unless you are having unsealed internal radiation
There also will be limits on visitors while your
implant is in place. Children younger than 18 or
pregnant women should not visit patients who are
having internal radiation therapy. Be sure to tell
your visitors to ask the hospital staff for any
special instructions before they come into your
room. Visitors should sit at least 6 feet from
your bed and the radiation oncology staff will
determine how long your visitors may stay. The
time can vary from 30 minutes to several hours per
day. In some hospitals a rolling lead shield is
placed beside the bed and kept between the patient
and visitors or staff members.
What Are the
Side Effects of Internal Radiation Therapy?
The side effects of implant therapy depend on the
area being treated. 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. If general
anesthesia was used while your implant was put in
place, you may feel drowsy, weak, or nauseated but
these effects do not last long. If necessary,
medications can be ordered to relieve nausea.
Be sure to tell the nurse about any symptoms that
concern you. In Section 4, "Managing Side
Effects," you will find tips on how to deal
with problems that might occur after implant
How Long Does
the Implant Stay in Place?
Your doctor will decide the amount of time that an
implant is to be left in place. It depends on the
dose (amount) of radioactivity needed for
effective treatment. Your treatment schedule will
depend on the type of cancer, where it is located,
your general health, and other cancer treatments
you have had. Depending on where the implant is
placed, you may have to keep it from shifting by
staying in bed and lying fairly still.
Temporary implants may be either low dose-rate (LDR)
or high dose-rate (HDR). Low dose-rate implants
are left in place for several days; high dose-rate
implants are removed after a few minutes.
For some cancer sites, the implant is left in
place permanently. If your implant is permanent,
you may need to stay in your hospital room away
from other people for a few days while the
radiation is most active. The implant becomes less
radioactive each day; 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.
What Happens After the Implant Is Removed?
Usually, an anesthetic is not needed when the
doctor removes a temporary implant. Most can be
taken out right in the patient's hospital room.
Once the implant is removed, there is no
radioactivity in your body. The hospital staff and
your visitors will no longer have to limit the
time they stay with you.
Your doctor will tell you if you need to limit
your activities after you leave 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 days at home, but you should
feel stronger quickly.
The area that has been treated with an implant may
be sore or sensitive for some time. If any
particular activity such as sports or sexual
intercourse cause irritation in the treatment
area, your doctor may suggest that you limit these
activities for a while.