NCCN Guidelines for Patients
Thyroid Cancer, Version 1.2017
If you have a CT scan with contrast, it can delay the
start of treatment with RAI therapy. Your doctor will
consider this when planning your care. A CT may be
necessary to see more of the neck or chest area to
check for disease.
The radiation itself will exit your body through urine
and other body fluids. Thus, your body will give off
small amounts of radiation after treatment. For a
short period, you may need to take special safety
measures around other people, especially children
or pregnant women. Ask your doctor to share a
complete list of instructions on your care before,
during, and after RAI therapy.
Radiation therapy uses high-energy rays to treat
cancer. The rays damage a cell’s instructions for
making and controlling cells. This either kills the
cancer cells or stops new cancer cells from being
made. Radiation can also harm normal cells and
cause side effects.
External beam radiation is sometimes given to treat
medullary and almost always given to treat anaplastic
thyroid cancer. Radiation may also be given when
the cancer does not respond to RAI therapy, if it
cannot be completely surgically removed.
Two ways radiation is given for thyroid cancer
given using a machine outside the body.
involves giving smaller doses of radiation for
a few weeks with x-ray beams of different
strengths based on the thickness of the tumor.
Radiation therapy plan and schedule
Before beginning radiation therapy, pictures of the
cancer in your body will be taken with a CT scan
using contrast. This process is called simulation.
Your radiation oncologist will use the pictures to
decide the radiation dose and to shape the radiation
beams. Beams are shaped with computer software
and hardware added to the radiation machine. PET
scans may also be used for radiation treatment
Your treatment team will decide the best time to
have radiation therapy after surgery. During radiation
treatment, you will lie on a table in the same position
as done during simulation. Devices may be used to
keep you from moving so that the radiation targets
the tumor. Likewise, methods may be applied to
You will be alone while the technician operates the
radiation 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.
One treatment session can take between 30 to 60
minutes. You will likely have 5 sessions a week.
Radiation may also relieve symptoms caused by
cancer. For thyroid cancer that has spread, this could
include difficulty or pain swallowing, loss of your
voice, or pain or stiffness in your neck. It is helpful to
ask your radiation treatment team for a complete list
of side effects and care instructions.
Common side effects of radiation to the neck area
Skin rash or redness
Extreme tiredness (fatigue)