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Radiation Therapy and Cancer Treatment

Radiation therapy is a type of cancer treatment. You may also hear it called radiotherapy or therapeutic radiology.

Radiation therapy kills cancer cells with high-energy X-rays, gamma rays, or charged particles. Like surgery, it can be used in many ways. It depends on what type of cancer you have and where it is in the body. Certain levels of radiation kill cancer cells or keep them from growing.

This treatment may be used to cure cancer. It may also help control the disease or ease symptoms that it's causing.

Most radiation treatments come from a large machine. It doesn't touch you. And it won't make you radioactive. Less often, a source of radiation may be put right into your body. Talk with your healthcare provider about any safety steps you need to take when getting this treatment.

What are the different types of radiation therapy?

Radiation therapy is given through different ways. The way you get it depends on the type of cancer, its place in your body, your overall health, and your preferences. This therapy is often used with other treatments. You may have it with chemotherapy or surgery. The types of radiation therapy are described below.

External radiation (external beam therapy)

A large machine points the radiation beams through your skin and right at the tumor. The beams are often aimed at the tumor from many different angles. A radiation therapist works the machine.

Radiation can affect nearby normal cells. So special shields may be made to protect the cells near the treatment zone. Most of the time, treatment is done 5 days a week for many weeks. These treatments don't hurt. They often last only a few minutes.

Internal radiation (brachytherapy, implant radiation, or systemic radiation)

A high dose of radiation is given inside the body. It's put as close to the cancer as possible. These implants are sometimes called seeds or capsules. They may be:

  • Swallowed

  • Injected into your blood

  • Put right into the tumor

  • Put next to the tumor through a body opening (such as the rectum)

Internal radiation lets you get a higher dose of radiation over a shorter time. Some sources of the radiation stay in the body for a short time. Others stay in the body forever. But they lose their energy over time. 

In some cases, both types of radiation therapy are used.

Before you get radiation therapy

Radiation should be aimed as precisely at the tumor as possible. This is important for treating the tumor. It also helps keep nearby normal tissues from getting too much radiation. That could lead to side effects. Each hospital may have certain procedures. But radiation therapy often goes this way:

Simulation process

You will first have a physical exam. Your healthcare provider will also review your health history. Your treatment team then maps out the position you'll be in for each treatment and the exact place on your body where the radiation will be given. This is called the treatment field or port. You may also have imaging studies. You may have CT scans, MRI scans, or PET scans. These may be used to help see exactly where the tumor is. This process takes a while. It often lasts a couple hours.

Sometimes, the skin over the part of your body to be treated will be marked with tiny dot tattoos. This is done to make sure radiation is given to the exact same place each time. The treatment team may also make casts, masks, molds, headrests, or other devices. These help put you in and keep you in the same spot for each treatment.

Treatment plan

Once the simulation process is done, a radiation oncologist will make your treatment plan. He or she will work with a team of experts. The plan will cover:

  • The type of radiation to use

  • How it will be given

  • The amount (dose) of radiation that's needed

  • The number of treatments you'll get

Online Medical Reviewer: Kimberly Stump-Sutliff RN MSN AOCNS
Online Medical Reviewer: Lu Cunningham
Online Medical Reviewer: Richard LoCicero MD
Date Last Reviewed: 2/1/2019
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