EXTERNAL BEAM RADIATION THERAPY TREATMENTS
When you undergo external beam radiation therapy treatment, each session is
painless, just like getting an X-ray. The radiation is directed at your tumor from a
machine located away from your body, usually a linear accelerator. External beam
radiation is noninvasive, unlike surgery which is an invasive process. One of the
benefits of radiation therapy is that it is usually given as a series of outpatient
treatments (meaning you don’t have to stay in the hospital). You may not need
to miss work or experience the type of recuperation period that may follow other
treatments.
Treatments are usually scheduled five days a week, Monday through Friday,
and continue for one to 10 weeks. The number of radiation treatments you will
need depends on the size, location and type of cancer you have, the intent of
the treatment, your general health and other medical treatments you may be
receiving.
The radiation therapist will give you your external beam treatment following your
radiation oncologist’s instructions. It will take five to 15 minutes for you to be
positioned for treatment and for the equipment to be set up. If an immobilization
device was made during imulation, it will be used during every treatment to
make sure that you are in the exact same position every day.
Once you are positioned correctly, the therapist will leave the room and go into the
control room next door to closely monitor you on a television screen while giving
the radiation. There is a microphone in the treatment room so you can always talk
with the therapist if you have any concerns. The machine can be stopped at any
time if you are feeling sick or uncomfortable.
The radiation therapist may move the treatment machine and treatment table to
target the radiation beam to the exact area of the tumor. The machine might make
noises during treatment that sound like clicking, knocking or whirring, but the
radiation therapist is in complete control of the machine at all times.
The radiation therapy team carefully aims the radiation in order to reduce the dose
to the normal tissue surrounding the tumor. Still, radiation will affect some healthy
cells. Time between daily treatments allows your healthy cells to repair much of the
radiation effect, while cancer cells are not as likely to survive the changes.
Sometimes a course of treatment is interrupted for a day or more. This may happen
if you develop side effects that require a break in treatment. These missed treatments
may be made up by adding treatments at the end. Try to arrive on time and not miss
any of your appointments. Time spent in the treatment room may vary depending on
the type of radiation, but it generally ranges from 10 to 40 minutes. Most patients are
treated on an outpatient basis, and many can continue with normal daily activities.
Your radiation oncologist monitors your daily treatment and may alter your radiation
dose based on these observations. Also, your doctor may order blood tests, Xrays
and other tests to see how your body is responding to treatment. If the tumor
shrinks significantly, another simulation may be required. This allows your radiation
oncologist to change the treatment to destroy the rest of the tumor and spare even
more normal tissue.
WEEKLY STATUS CHECKS
During radiation therapy, your radiation oncologist and nurse will see you regularly to
follow your progress, evaluate whether you are having any side effects, recommend
treatments for those side effects (such as medication), and address any concerns you
may have. As treatment progresses, your doctor may make changes in the schedule
or treatment plan depending on your response or reaction to the therapy.
Your radiation therapy team may gather on a regular basis with other healthcare
professionals to review your case to ensure your treatment is proceeding as planned.
During these sessions, all the members of the team discuss your progress as well
as any concerns.
WEEKLY IMAGING
During your course of treatment, correct positions of the treatment beams will
be regularly verified with images made using the treatment beam itself. These
images (called port films, or portal verification) represent an important quality
assurance check, but do not evaluate the tumor itself.
BRACHYTHERAPY
Brachytherapy is the placement
of radioactive sources in or
just next to a tumor. The word
brachytherapy comes from the
Greek “brachy” meaning short
distance. During brachytherapy,
the radioactive sources may
be left in place permanently or
only temporarily, depending
upon your cancer. To position
the sources accurately, special
catheters or applicators are
used.
There are two main types of brachytherapy — intracavitary treatment and
interstitial treatment. With intracavitary treatment, the radioactive sources are
put into a space near where the tumor is located, such as the cervix, the vagina or
the windpipe. With interstitial treatment, the radioactive sources are put directly
into the tissues, such as the prostate.
Sometimes these procedures require anesthesia and a brief stay in the hospital.
Patients with permanent implants may have a few restrictions at first and then can
quickly return to their normal activities. Temporary implants are left inside of your
body for several hours or days. While the sources are in place, you will stay in a
private room. Doctors, nurses and other medical staff will continue to take care of
you, but they will take special precautions to limit their exposure to radiation.
Devices called high-dose-rate remote afterloading machines allow radiation
oncologists to complete brachytherapy quickly, in about 10 to 20 minutes. Powerful
radioactive sources travel through small tubes called catheters to the tumor for the
amount of time prescribed by your radiation oncologist. You may be able to go
home shortly after the procedure. Depending on the area treated, you may receive
several treatments over a number of days or weeks.
Most patients feel little discomfort during brachytherapy. If the radioactive source
is held in place with an applicator, you may feel discomfort from the applicator.
There are medications that can relieve this discomfort. If you feel weak or queasy
from the anesthesia, your radiation oncologist can give you medication to make you
feel better.
Depending on the type of brachytherapy you received, you may need to take some
precautions after you leave your treatment, particularly if you plan to be around
young children or pregnant women. Ask your radiation oncologist or radiation
oncology nurse about anything special you should know.