NCCN Guidelines for Patients
Prostate Cancer, Version 1.2016
4 Overview of cancer treatments
Radiation therapy is a cancer treatment that uses
high-energy rays. The rays damage DNA. This either
kills the cancer cells or stops new cancer cells from
being made. Radiation can also harm normal cells.
Radiation therapy is an option for many men with
prostate cancer. Radiation therapy may be given to
your pelvic lymph nodes as well as to your prostate.
The two ways to give radiation are discussed next.
External beam radiation therapy
Most often, EBRT (
is the method used to treat prostate cancer. This
method delivers radiation from outside your body
using a large machine. The radiation passes through
your skin and other tissue to reach the tumor.
Treatment planning with a simulation session is
needed. During simulation, pictures of the tumor will
be taken with an imaging scan. Pictures are taken
after your body is moved into the position needed for
Using the scans, your treatment team will plan the
best radiation dose, number and shape of radiation
beams, and number of treatment sessions. Beams
are shaped with computer software and hardware
added to the radiation machine. Radiation beams are
aimed at the tumor with help from ink marks on the
skin or marker seeds in the tumor.
During treatment, you will lie on a table in the same
position as done for simulation. Devices may be used
to keep you from moving so that the radiation targets
the tumor. You will be alone while the technician
operates the machine from a nearby room. He or she
will be able to see, hear, and speak with you at all
As treatment is given, you may hear noises. One
session often takes less than 10 minutes. EBRT is
given 5 days a week for about 8 to 9 weeks, although
there is growing interest in shortening the length of
Often, ADT (
herapy) is used
with EBRT. ADT is described later in this chapter.
Many studies have shown that adding ADT to EBRT
improves treatment outcomes when prostate cancers
are more aggressive. ADT has side effects so it
shouldn’t be used unless needed. Some men require
short-term (4 to 6 months) ADT. Other men are on
ADT for 24 to 36 months.
There are multiple types of EBRT. For prostate
cancer, 3D-CRT (
herapy) or IMRT (
herapy) may be used. In 3D-CRT, the
radiation beams match the shape of your tumor to
avoid healthy tissues. IMRT is a more precise type
of 3D-CRT that may be used especially for more
aggressive prostate cancer. The radiation beam is
divided into smaller beams, and the strength of each
beam can vary.
The prostate can slightly shift within the body. Tumors
may also change shape and size between and during
treatment visits. IGRT (
herapy) can improve how well 3D-CRT and IMRT
target the tumor.
IGRT uses a machine that delivers radiation and also
takes pictures of the tumor. Pictures can be taken
right before or during treatment. These pictures are
compared to the ones taken during simulation. If
needed, changes will be made to your body position
or the radiation beams.
There are different types of radiation beams. 3D-CRT
and IMRT are x-ray–based treatments. They use