Healthcare professionals use external beam radiation therapy (EBRT) to treat many types of cancer. They also use it to treat some noncancerous tumors and other conditions.

Radiation therapy involves using beams of photons, X-rays, or other high-energy particles to damage the DNA of cancer or other atypical cells. This can stop them from replicating.

In EBRT, a healthcare professional will administer the radiation from a large machine outside your body. The machine will direct the radiation toward cancerous tissue inside your body.

Radiation therapy can be lifesaving for people who need it, either by itself or combined with other treatments. Some people experience side effects because the radiation may also damage healthy tissue around the treatment site.

In this article, we examine the benefits and risks of EBRT, as well as how the procedure works.

Radiation therapy is a common cancer treatment. Nearly one-third of people with cancer receive radiation. By 2030, it’s estimated that there will be 4.17 million radiation-treated cancer survivors in the United States.

Doctors use EBRT as a cancer treatment in several ways:

  • by itself or with other treatments to try to cure the cancer
  • before other treatments like surgery to shrink a tumor
  • after other treatments to destroy any remaining cancer cells
  • after other treatments to reduce symptoms and prolong quality of life

They use EBRTto treat a wide range of cancers, including:

Radiation therapy can also potentially cure or reduce symptoms from some noncancerous tumors, such as:

Other conditions treated with radiation therapy include:

  • Arteriovenous malformations: Arteriovenous malformations are atypical connections between your veins and arteries present from birth. They’re sometimes treated with a special type of EBRT called Gamma Knife.
  • Cushing syndrome: Cushing syndrome is a collection of symptoms that occur when your pituitary gland produces too much adrenocorticotropic hormone. Doctors sometimes use radiation to treat pituitary tumors that lead to Cushing syndrome.

General side effects of EBRT include:

Here are some examples of specific side effects:

LocationSide effects
• memory or concentration difficulties
nausea and vomiting
breast• swelling
• tenderness
chesttrouble swallowing
• shortness of breath
head and neck• mouth issues
changes to your taste
• trouble swallowing
pelvis, abdomen, or rectumdiarrhea
• nausea and vomiting
• sexual or fertility concerns
• urinary and bladder issues

Radiation exposure can increase your risk of developing another cancer, so doctors limit your lifetime dose.

Learn more about radiation side effects.

Here’s what you can expect during your procedure:

  1. You may have to change into a hospital gown, depending on where you’re receiving treatment.
  2. You’ll be asked to lie on the treatment table underneath a large machine that administers the radiation. Your radiation therapist may put shields on parts of your body not being treated to protect them.
  3. Your technician will move you into the treatment position and make sure the machine is aimed at the proper location.
  4. They will go into a nearby room that protects them from the radiation to operate the machine. They’ll still be able to see you on a screen and can communicate with you through a speaker.
  5. The machine will make noises such as clicks and buzzing as it moves and administers radiation from different angles. You shouldn’t feel any pain during the procedure.

Before your treatment, you’ll likely undergo imaging tests like CT scans or MRI scans. This will help your healthcare professional figure out exactly where to administer the radiation. You’ll also likely receive marks on your skin with a dye to help pinpoint the location.

Side effects are often worse within the first 2 weeks of treatment. Most side effects should go away within a couple of months but some can persist for months to years.

The effectiveness of EBRT depends on what it’s used to treat. When used to treat cancer, the effectiveness depends on factors like:

  • your overall health and age
  • the dosage and type of radiation administered
  • the type of cancer you have
  • the extent of the cancer

EBRT is highly effective at treating some types of cancers. For example, breast-preserving surgery followed by whole breast radiation therapy is the preferred treatment for early breast cancer.

Radiation therapy generally isn’t effective for treating cancer that has spread beyond the original site, but it may help manage symptoms and prolong life.

The cost of EBRT depends on factors like:

  • the extent and area of your treatment
  • where you live
  • your clinic or hospital
  • your type of radiation therapy

For reference, in a 2018 study, researchers reported the cost of radiation therapy for cervical cancer as $12,861.68, of which $4,055.01 was from EBRT.

In a 2020 Canadian study, researchers estimated the following average cost of radiation therapy at various sites in the province of Ontario:

SitePrice (Canadian)Approximant USD
breast cancer$18,529$13,736
colorectal cancer$15,177$11,251
lung cancer$10,818$8,020
prostate cancer$16,887$12,519

Almost all major insurance providers, including Medicare, cover the cost of radiation therapy if it’s deemed medically necessary. They might not cover it if it’s considered an experimental treatment. They may also not cover a newer but more expensive type of radiation therapy called proton therapy.

Radiation therapy is just one of many cancer treatments. Other potential treatment options include:

Cushing syndrome and arteriovenous malformations can also be treated with medications and surgery.

Here are some frequently asked questions people have about EBRT.

How long does external beam radiation take?

Usually, EBRT is administered 5 days per week for 5–8 weeks, according to the American Cancer Society. Each treatment session usually takes only 15–30 minutes including the time it takes to set up the equipment.

What is the survival rate following external radiation therapy?

Survival rates vary by cancer type and stage. In a 2018 study, researchers reported 5-year prostate cancer survival rates of 77.4% in people who received radiation therapy after not responding to hormone therapy.

In another study from 2019, researchers found that 42% of people who had cancer that had spread to their brain and received radiation therapy lived at least 1 year.

EBRT is used to treat many types of cancer, either by itself or combined with other treatments. It’s an essential treatment tool for a wide range of cancers and some other conditions.

Your healthcare team can help you decide if you may benefit from EBRT or whether other treatments may offer better outcomes. Although EBRT can be lifesaving, it can also cause many side effects that affect your quality of life.