Radiation Therapy

Radiation therapy — or radiotherapy — is a common treatment that uses radiation (usually high-powered X-rays) to kill cancer cells and shrink cancerous tumors. It can also ease cancer symptoms. You may have it alone or with surgery or chemotherapy. Radiation therapy is also treatment for some noncancerous conditions.

Radiation therapy types

There are two types: external beam radiation therapy (EBRT) and internal radiation therapy. Both types treat cancer by destroying cancer cells’ DNA. The cells need DNA instructions to grow and multiply. Without them, cancer cells die, and tumors shrink. Healthcare providers may use low-dose EBRT to treat noncancerous conditions.

External beam radiation therapy

This is the most common type of radiation therapy. In EBRT, a machine directs beams of high-energy radiation toward the tumor. The energy may be X-rays (most common), electrons or protons. The machine may move around your body, but it never touches you. There are many forms of EBRT:

• 3D CRT: This form uses CT scans and computer software to create a 3D model of the tumor. The model guides the machine to focus beams on the tumor.
• Intensity-modulated radiation therapy (IMRT): IMRT focuses high-dose beams on the cancer while avoiding healthy tissue.
• Image-guided radiotherapy (IGRT): You may have IGRT if you have cancer in an area of your body that moves during treatment. Your team will do imaging tests before and during treatment so the treatment stays focused on the tumor.
• Proton therapy: This treatment destroys tumors with high-energy particles (protons).
• Stereotactic radiosurgery: This treatment targets small brain tumors with a high dose of radiation in one or more sessions (fractions).
• Stereotactic body radiation therapy (SBRT): This form treats tumors outside of your brain, like early-stage lung cancer or kidney cancer.
• Intraoperative radiation (IORT): You may have this treatment during surgery to remove a tumor. IORT destroys any cancer cells that surgery may not remove.
• Low-dose radiation therapy (LDRT): Providers may use lower doses of radiation to treat a wide range of conditions, including osteoarthritis, ventricular tachycardia and benign (noncancerous) tumors.

Internal radiation therapy

Internal radiation therapy works by placing radioactive materials inside your body. It’s a treatment for smaller tumors in your head, neck, breast, cervix, uterus or prostate. There are two types of this treatment:

• Brachytherapy: This involves placing a solid radioactive source, known as a seed or implant, inside or beside a tumor. Some implants release low doses over several days or weeks. Others may release high doses over much shorter periods of time.
• Systemic therapy: In this treatment, you receive liquid radioactive material through your blood. You may have an injection through a vein or swallow a pill.

Who provides radiation therapy?

A team of specialists will manage your treatment. The team will develop a treatment plan that uses radiation dosages to destroy cancer cells without harming nearby healthy tissue. The team will include your:

• Radiation oncologist: This provider directs your treatment. They’ll work with your care team to confirm radiation therapy is the best option for your situation. If so, they’ll recommend the best type for your situation.
• Medical physicist: This professional makes sure treatment equipment delivers radiation accurately.
• Dosimetrist: This team member helps to design the treatment plan.
• Radiation therapist: This provider helps you prepare for treatment and operates the machine that delivers radiation.

What happens before radiation therapy?

You’ll have a physical exam, and your team will do imaging tests like a CT scan. They’ll explain how you can prepare for the day of the procedure based on how you’ll receive the radiation.

EBRT involves planning sessions (simulations). These sessions are how your team creates the best treatment setup. The goal is treatment that’s best for your situation. Simulation involves:

• Getting in position: You’ll lie on a treatment table in the position you’ll be in during treatment. Your care team may use a mold or mask to hold your body in place. They may place temporary or permanent markings (tiny dots) that show the specific treatment area.
• Getting scans: Your team will do a CT scan or an MRI so they can see the tumor. This helps them target the exact area.

What happens during radiation therapy?

EBRT and internal radiation therapy involve different steps.

External body radiation therapy

With EBRT, you lie on a treatment table in the same position you were in during the simulation. The machine moves around you but never touches you. You won’t feel anything during treatment.

Internal radiation therapy

Your treatment may take place in a special outpatient room or in a hospital. You’ll receive anesthesia so you don’t feel pain or discomfort during your treatment. Your radiation oncologist uses a small, flexible tube to insert the seed or implant. You’ll receive radioactive fluid through an IV (in your vein) or take pills if you have systemic treatment.

This radiation type focuses directly on cancer cells. Your body will be radioactive for a certain time. Your radiation care team will explain how long radiation will remain in your body. They’ll also explain any steps you should take to avoid affecting others.

What happens after treatment?

You should be able to continue your daily routine after EBRT. Your situation may be different if you have internal radiation therapy:

• Systemic (IV) radiation therapy: Your body will shed trace amounts of radiation through body fluids like your sweat, saliva, blood and pee. You may need to stay in the hospital for one to two days while radiation leaves your body.
• Permanent implant: There’s a small risk that you may expose others to radiation. Your radiation therapy team will discuss how you can avoid exposing others.

How long will I need this radiation therapy?

In general, external beam radiation therapy lasts up to six weeks. The different forms of internal radiation therapy may take a single day or several weeks.

How successful is this treatment?

Radiation therapy is one of the most powerful cancer treatments. But just like cancer isn’t a single disease, there’s no single success rate. As you think about your options, ask your team about the success rates for the treatment they recommend.

What are the potential benefits and risks of radiation therapy?

This treatment may cure some kinds of cancer. It can help other treatments work better. And radiation therapy can ease some cancer symptoms. But it may increase the chance you’ll develop a different cancer. For many people, the benefits of radiation therapy are worth the risk. Your radiation oncologist will discuss this risk with you before you start your treatment.

When can I get back to my normal routine?

Everyone’s situation is a bit different. Some people can go back to their daily routines without any issue. Others experience side effects like fatigue or changes in their skin. Your care team will discuss any potential side effects and how they’ll help you to manage them.

When should I call my healthcare provider?

Let your care team know about side effects that are more severe than you expect. They can prescribe medication to ease side effects. They may be able to adjust your dosage, change your treatment or try a different one.