Thymus Cancer: Radiation Therapy

What is radiation therapy?

Radiation therapy uses high-energy beams of X-rays or particles to kill cancer cells.

When might radiation therapy be used?

Radiation is part of the treatment for some thymus tumors. These are some of the reasons your healthcare provider may recommend radiation:

  • To try to kill any cancer cells that might be left after surgery. When radiation is used after surgery, it’s called an adjuvant therapy. 

  • To try to shrink a tumor before surgery. This might make it easier to remove. When radiation is used before surgery, it’s called a neoadjuvant therapy.

  • To treat the tumor if you can't have surgery for some reason.  In this case, radiation is often given along with chemotherapy. This is sometimes called chemoradiation.

  • To ease symptoms  caused by tumors that can't be treated with surgery or that have spread to other organs. For instance, to shrink a tumor that's causing swallowing or breathing problems.

To make your radiation treatment plan, you'll meet with a team of cancer specialists. This might include a surgeon, radiation oncologist, and medical oncologist.

What happens during radiation therapy

The most common way to get radiation for a thymus tumor is from a machine outside your body. This machine sends out an invisible beam of energy. This is called external radiation. Sometimes special types of external radiation are used to try to limit the doses of radiation reaching nearby normal cells. This includes intensity-modulated radiation therapy (IMRT) and 3-D conformal radiation therapy (3D-CRT).

A doctor who specializes in cancer and radiation is called a radiation oncologist. This doctor works with you to decide the kind of radiation you need. This doctor also figures out the dose and how long you need treatment.

Most people get external radiation on an outpatient basis in a hospital or clinic. This means you go home after each treatment. Most people get radiation 5 days a week for many weeks.

Getting ready for radiation

Before your first radiation treatment, you’ll have a session to figure out exactly where on your body the radiation beam needs to be directed. The process is called simulation. It may take up to 2 hours. During this session, you may have imaging tests, such as CT scans or MRI scans. These can help your healthcare providers know exactly where the tumor is to better aim the radiation. Also at this session, you may have body molds made to help put you in the same position and keep you from moving during each treatment. 

Then, you’ll lie still on a table while a radiation therapist uses a machine to define your treatment field. The field is the exact area on your body where the radiation will be aimed. Sometimes it’s called your port. The therapist may mark your skin with tiny dots of semi-permanent ink or tattoos. This is done so the radiation will be aimed at the exact same place each time. 

On the days you get radiation

On the days you get radiation treatment, you’ll lie on a table while the machine is placed over you. You may have to wear a hospital gown. It’s a lot like getting an X-ray, only longer. It takes about 15 to 30 minutes to complete. But you should plan on being there for about an hour.

At the start of the treatment session, a radiation therapist may use blocks or special shields to protect parts of your body that don’t need to be exposed to radiation. The therapist then sets up the machine so that lights from the machine line up with the marks on your skin that were made during simulation. When you’re ready, the therapist leaves the room and turns the machine on. You may hear whirring or clicking noises, a lot like the sounds of a vacuum cleaner, while the radiation is being given. During the session, you’ll be able to talk to and hear the therapist over an intercom. The therapist can see you the whole time. The machine won't touch you and you can’t feel radiation, so the process won't hurt. Also, you won’t be radioactive afterward.

What to expect after radiation therapy

Because radiation affects normal cells as well as cancer cells, you may have some side effects. The side effects from radiation are usually limited to the area being treated. Some people have few or no side effects. But if you have them, your healthcare provider may change the dose of radiation or how often you get treatments. Or your healthcare provider may stop treatment until the side effects clear up. Be sure to tell your healthcare provider about any side effects you have.

Possible short-term side effects

These are some of the common short-term side effects:

  • Skin irritation or changes where the radiation goes into your body. This can be like a bad sunburn. Your skin may blister and peel.

  • Nausea 

  • Fatigue

  • Irritation of your esophagus. This could lead to eating problems such as pain when swallowing.

  • Loss of appetite and weight loss

If you have any side effects, ask your healthcare provider or nurse how to best deal with them. Also ask how to know when they become serious. Most side effects can be treated, and some can even be prevented. Side effects normally go away over time after you stop getting treatment.

Potential long-term side effects

Radiation can cause some long-term side effects. These depend on where the radiation was aimed. This is a special concern when treating tumors in young adults. Long-term side effects can include:

  • Lung damage. Radiation might harm your lungs. This could lead to trouble breathing and shortness of breath.

  • Increased risk of heart disease. This includes heart attacks.

  • Second cancers. Cancers are more likely to form in areas that have received radiation. These cancers may form even decades after treatment.

Online Medical Reviewer: Kimberly Stump-Sutliff RN MSN AOCNS
Online Medical Reviewer: Lu Cunningham
Online Medical Reviewer: Richard LoCicero MD
Date Last Reviewed: 4/1/2019
© 2021 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare provider's instructions.