Radiation Therapy

What is radiation therapy?

Radiation therapy uses high-energy radiation (X-rays) to kill cancer cells and shrink or destroy tumors.

Radiation therapy may:

  • Cure some cancers
  • Shrink tumors and lessen the symptoms
  • Help stop the spread of cancer

Radiation therapy is sometimes called X-ray therapy, radiotherapy, or irradiation.

When is it used?

Cancer cells grow and multiply more quickly than normal cells. Carefully planned doses of radiation can kill or stop the growth of the fast-growing cancer cells. Most normal cells can recover from the radiation.

Radiation therapy may be used to:

  • Shrink a tumor before surgery, which makes it easier to remove the tumor
  • Destroy cancer cells that remain after surgery or other treatments
  • Destroy cancer when used along with chemotherapy
  • Control the size of the tumor and limit its spread in order to treat pain, pressure, and other symptoms

Radiation therapy alone can cure some cancers, such as Hodgkin’s disease. However, for most cancers it is used along with surgery or chemotherapy, which uses medicine to kill cancer cells.

You may choose not to have treatment. Ask your healthcare provider about your choices for treatment and the risks.

How do I prepare for this procedure?

Ask your radiation doctor what your schedule will be and how you should expect to feel.

  • Plan for your care and find someone to give you a ride home after the procedure.
  • Tell your provider if you have had kidney problems or an allergy to chemicals, such as contrast dye. Contrast dye is used for some scans.
  • You may or may not need to take your regular medicines the day of the procedure, depending on what they are and when you need to take them. Tell your healthcare provider about all medicines and supplements that you take.
  • Follow any instructions your healthcare provider gives you.
  • Ask any questions you have before the procedure. You should understand what your healthcare provider is going to do and how the treatments are likely to make you feel.
  • You will have one appointment before you start getting radiation to mark the areas that will be getting radiation. These ink marks on your skin will come off when you complete your treatment.

What happens during the procedure?

There are 2 kinds of radiation therapy: external and internal.

External radiation

External radiation is delivered from outside the body. It is usually given during outpatient visits to a hospital or treatment center.

The ink marks on your skin will show the radiation technologist the exact area to be treated. You will lie on a treatment table. A machine will direct a beam of radiation at the tumor. Each external radiation treatment lasts just a few minutes. The treatment is painless.

Everyone’s treatment schedule is different. You may have a few short treatments over a few days or your may have treatments every day for weeks. During treatment, the therapist will weigh you and may do tests, such as blood cell counts, to check the effect the radiation is having on your body.

After your last session, the therapist will wipe the ink marks off your body.

Internal radiation

For internal radiation therapy, the radiation source may in the form of seeds, ribbons, or capsules, which are put inside your body near the cancer cells. This treatment uses a high dose of radiation to a small part of your body. It may be used to treat cancers of the head, neck, breast, uterus, cervix, prostate, gallbladder, eye, and lung.

Internal radiation can also be in a liquid form that you drink, swallow as a pill, or get through an IV. Liquid radiation goes all through body to kill cancer cells. You may have the liquid form if you have thyroid cancer or non-Hodgkin’s lymphoma

When the radiation source is put in, you may be given general anesthesia to relax your muscles, put you to sleep, and keep you from feeling pain, or you may be given a local anesthetic to numb the area.

The radiation source may stay in place for a few minutes, several days, or for the rest of your life. How long it stays in place depends on your type of cancer, where the cancer is in your body, your health, and other cancer treatments you have had.

What happens after the procedure?

Ask your healthcare provider:

  • How long it will take to recover
  • What activities you should avoid, including how much weight you can lift and when you can return to your normal activities
  • How to take care of yourself at home
  • What symptoms or problems you should watch for and what to do if you have them

Make sure you know when you should come back for a checkup.

What are the risks of this procedure?

While it is killing tumor cells, radiation therapy can also damage normal cells in the area of the tumor. Side effects depend on the part of the body that is getting the treatment. Some possible side effects are:

  • Skin sores or darkening of the skin
  • Loss of head and body hair
  • Increased risk of infection
  • Bleeding problems
  • Nausea, vomiting, and diarrhea
  • Weakness, tiredness, and fatigue
  • Sores in the mouth
  • Loss of appetite

If the side effects get severe, treatment may be stopped for a while, or the dose may be lowered. In extreme cases, treatment may be stopped completely and other treatment options may be considered.

Your healthcare provider will explain the procedure and any risks. Some possible risks include:

  • There is a risk of hurting healthy cells.
  • Your skin could get scarred or get darker.
  • Depending on the area being treated, your bowel, or bladder, or other organs could be injured.
  • If you are having both radiation therapy and chemotherapy, you may have more side effects.
  • If you have internal radiation therapy, the radioactive material may send its high-energy rays outside your body. This means that other people in close range may be exposed to small doses of radiation. You will be given instructions about if, when, and how long other people can be around you while you have the implant. You don’t have to worry about exposing others to radiation if you are treated with external radiation.
  • The radiation therapy may not destroy all of the cancer.
  • The cancer may come back.

There is risk with every treatment or procedure. Ask your healthcare provider how these risks apply to you. Be sure to discuss any other questions or concerns that you may have.

Developed by RelayHealth.
Adult Advisor 2015.1 published by RelayHealth.
Last modified: 2014-02-20
Last reviewed: 2014-09-10
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright ©1986-2015 McKesson Corporation and/or one of its subsidiaries. All rights reserved.

Patient Portal

Our Patient Portal provides safe and secure online access to better communicate with your Tufts Medical Center Community Care doctor. This easy-to-use web tool is a convenient way to book appointments, request referrals, renew prescriptions, view medical records/test results and communicate with your healthcare provider from the privacy of your own computer.


Your privacy is important to us. Learn more about ourwebsite privacy policy. X