NCCN Guidelines for Patients
Colon Cancer, Version 1.2017
Overview of cancer treatments
During treatment, you will lie on a table as you did for
simulation. Devices may be used to keep you from
moving. This helps to target the tumor. Radiation
beams are aimed with help from ink marks on your
skin or marker seeds in the tumor.
You will be alone in the treatment room. A technician
will operate the machine from a nearby room. He or
she will be able to see, hear, and speak with you at
all times. As treatment is given, you may hear noises.
You will not see, hear, or feel the radiation. One
session can take less than 10 minutes.
radiation inside your body at the time of an operation.
Different methods can be used. However, the usual
method involves a device that is placed where the
tumor was. The radiation kills remaining cancer cells
in the tissue that was near the tumor.
IORT is a one-time treatment that is given while
you are still asleep. It can deliver a radiation dose
similar to EBRT or deliver extra radiation. This extra
radiation is called a boost. IORT uses radiation made
of electrons. Electrons do not travel far and are less
likely to harm the tissue beneath the treatment site.
Some cancer centers do not have an IORT machine.
In this case, a boost of radiation can be given with
EBRT or brachytherapy. Brachytherapy delivers
radiation through radioactive objects that are placed
where the tumor was. The objects remain in your
body for a short period of time following surgery.
Brachytherapy is rarely used for colon cancer.
Side effects from radiation therapy differ among
people. Factors like method, treatment site, radiation
dose, and length of treatment play a role. However,
many people feel tired (fatigue) no matter the
radiation method or site.
When EBRT is used, skin damage is also common
right after treatment. Your skin will heal shortly after
treatment ends. You may also have short-term hair
loss, but only where treated.
Chest radiation can cause a dry cough or a sensation
of a lump when you swallow. Radiation near your
belly can cause nausea and maybe vomiting. When
given between your hip bones, radiation can cause
frequent bowel movements. Your stool may be loose
(diarrhea) and you may have cramps or pain in your
IORT and brachytherapy can cause side effects
like EBRT. You may feel nauseated and may vomit.
Frequent bowel movements and urination may occur.
Late side effects of radiation can happen. Again,
the effects depend on the treatment site. Examples
include lung scarring, heart disease, infertility, and
Not all side effects of radiation are listed here.
Please ask your treatment team for a complete list of
common and rare side effects. If a side effect bothers
you, tell your treatment team. There may be ways to
help you feel better. There are also ways to prevent
some side effects.