Radiation Oncology

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Radiation Oncology Facts

Radiation oncology is a branch of medicine that treats cancer by using high-energy radiation in the form of photons (such as X-rays or gamma rays) or subatomic particles (such as electrons or protons). About 60 percent of people with cancer receive radiation therapy, according to the American Cancer Society.

How Does Radiation Therapy Work?

Radiation therapy (also called radiotherapy) works by damaging the DNA inside the cancer cells. When the DNA sustains enough damage, the cells cannot multiply, and they die. The goal of radiation therapy is to destroy as many cancer cells as possible with the least amount of damage to healthy cells.

Why Is Radiation Therapy Used?

The exact role of radiation therapy in your care depends on many factors, including the type, size, location, and stage of your cancer. Radiation therapy may be used as any of these:

  • Primary treatment. This means it’s the main treatment you receive to cure, stop, or slow the disease. 
  • Adjuvant therapy. This means you receive it after one or more other treatments, like surgery or chemotherapy, to reduce the risk that your cancer will come back.
  • Palliative therapy. This means it’s used to relieve symptoms, like pain, by shrinking your tumor.

Your Radiation Oncology Team

A team of health care professionals works together to deliver radiation therapy. A team typically includes these people:

  • Radiation oncologist. This is a doctor who specializes in treating cancer with radiation. This doctor will prescribe, plan, and oversee your radiation treatment.
  • Radiation therapist. When you come in for radiation treatment, this person will position you for your treatment and operate the machines that deliver the radiation.
  • Radiation oncology nurse. This is a nurse who will explain your treatment, answer your questions, and help you manage side effects.

Some members of the radiation oncology team work behind the scenes.

  • Medical dosimetrist. This person will complete the calculations needed to carry out your treatment to ensure that you receive the exact dose of radiation prescribed by your radiation oncologist in precisely the right places. 
  • Medical physicist. This person will help plan your treatment and will maintain the equipment used to deliver radiation therapy.

Types of Radiation Therapy

To treat cancer, radiation therapy can be delivered using a machine outside the body—called external-beam radiation therapy—or it can be delivered internally, such as by implanting small radioactive seeds.