Radiation therapy: What it is and what to expect

More than half of cancer patients will receive radiation therapy, but what is it? Does it hurt?
And what are the side effects?

We spoke with Cullen Taniguchi, M.D., Ph.D., to answer some
common questions about radiation therapy. Here’s what he had to share.

How does radiation therapy work?

Radiation therapy uses high-energy waves, like those used with an
X-ray, but at a higher energy that damages tumor cells’ DNA. The tumor
cells die, but the surrounding normal tissues heal themselves.

When is radiation therapy typically used?

There are three ways radiation is used. Most commonly, radiation is
used before surgery to shrink a tumor so that it’s easier to remove.
We also give radiation after surgery to help destroy any remaining
cancer. And when tumors can’t be easily removed with surgery, we’ll
use radiation instead.

What are the different types of radiation therapy?

Brachytherapy allows us to put radiation up close to the tumor. But
we can only do this safely with a few tumor types, such as with prostate cancer, cervical cancer and breast cancer.

A second type of radiation uses photons, which you may know as
X-rays. We first identify the tumor’s location with a CT scan. Then,
we develop a plan to ensure as little normal tissue is exposed to
radiation as possible. Intensity-modulated radiation therapy (IMRT) is
a type of photon therapy that uses a powerful computer to help develop
the treatment plan. The computer uses multiple angles to identify the
best approach to kill the tumor and limit exposure to normal tissue.
IMRT is used when a tumor is close to sensitive organs, such as with
anal cancer where the tumor is near the small intestine and genitalia.

The third type of radiation therapy is proton therapy. It’s different from other types
of radiation in that the energy waves don’t pass through your body and
instead stop at the tumor site. This limits radiation exposure to
healthy tissues. Currently, proton therapy is used to treat prostate
cancer, lung cancer, head and neck cancers, liver cancer, bile duct cancer and pediatric tumors.

What should I expect the day of my first radiation?

It’s just like getting a CT scan. You’ll walk into a large room that
has a table and an open-air machine. The machine is equipped with
cameras and microphones so we can talk during the treatment. You’ll
lie down on a table, and the machine will circle around you. You won’t
ever see the radiation, and you won’t feel it at your first treatment. 

What are common radiation therapy side effects?                                                                                          

Side effects depend on the site of your radiation, but a universal
one is fatigue. My patients say they feel like they need
an extra nap in the afternoon, and I say listen to your body.

Some patients also have nausea, and we have good medications to provide
relief. Other common side effects include skin redness and diarrhea.

Some side effects don’t show up until some time has passed — in
some cases years. In terms of long-term side effects, patients may
also experience skin changes, such as hardening and darkening, at the
site of treatment.

The patients that do the best are those who get ahead of the
symptoms, so talk to your care team early on about possible side effects.

What lifestyles changes should I make while receiving
radiation therapy?

Focus on good
nutrition. You’ll need to consume more calories
than usual to fuel the body’s work of repairing any damage to normal
tissues surrounding the treatment site.

Unfortunately, it’s very common to not have an appetite because of
the cancer or the treatment, but I tell patients to think of food as a
prescription. You need to get the right nutrition to help with
healing. If you’re an MD Anderson patient,
ask for a referral to see one of our dietitians if you’re having
trouble eating.

I also recommend patients be as active as their bodies will let
them. Staying active is good for the body and the mind, though this
isn’t the time to start a new fitness regimen.

What’s new with radiation therapy?

One innovation is stereotactic radiation, which is a form of IMRT.
It allows us to safely deliver a radiation at such as high dose that
we can shorten the length of treatment to as little as one week, and
sometimes even one day. By reducing the treatment period, a patient
can receive radiation during a “down week” of their chemotherapy
schedule. It’s more convenient, and it can cost less than standard
radiation treatments. Stereotactic radiation is already being used for
lung cancer and tumors in the brain and spine. We’ll be opening a clinical trial very soon to see if it’ll also
work on other diseases.

We’re also looking into how immunotherapy can work with radiation. After
radiation, a tumor remains in the body as scar tissue and is slowly
removed by the immune system. We’re exploring how to combine our
treatments with immunotherapy drugs to trigger the immune system to
fight tumors. We hope to start enrolling patients in our clinical
trials soon.

Request an appointment at MD Anderson online or by
calling 1-877-632-6789.