Radiation for a Brain Tumor

The goal of radiation therapy is to slow or control tumor growth. In some cases, it may fully remove a tumor. It uses painless radioactive rays or substances to destroy tumor cells. Radiation therapy can be used alone. Or it can be used with other types of treatment. You may also have surgery or chemotherapy. If your healthcare provider advises radiation therapy for you, you may have one of the below.

External beam radiation

There are several types of this therapy. They include:

  • 3-D conformal radiation therapy (3DCRT). This treatment sends radiation from many angles. It helps to reduce damage to nearby tissues.

  • Intensity modulated radiation therapy (IMRT). This uses a machine controlled by a computer. The machine moves around your head as it sends radiation into your body. The angles and strength of the radiation beams can be changed to fit the shape of the tumor.

  • Whole brain radiation. This is used to treat more than one tumor. Or it may be used on cancer that has spread through the brain. It sends radiation to the entire brain. It may have more severe side effects.

  • Stereotactic radiosurgery. This is done with a single high dose of radiation aimed right at the tumor from many angles with a machine. It may be given in several high doses. Since it is very focused, the normal tissue around the tumor gets little or no radiation. There are 2 types of machines most often used for this treatment.  One is the Gamma Knife. This machine sends gamma rays. The other machine is a linear accelerator. This uses X-rays. One name for this machine is the Cyberknife.

Internal radiation (brachytherapy)

This type of treatment puts radiation right near the cancer tissue. Small radioactive seeds or a balloon filled with a liquid radiation are placed into or near the brain tumor during surgery.  The radiation only travels a short distance in the body so damage to nearby tissue is reduced. Radioactive seeds are used most often. Stronger seeds may be removed after a few minutes or after up to 7 days. Weaker seeds may stay in place ongoing. These then become inactive over time.

Side effects of radiation therapy

Side effects vary depending on factors such as:

  • Type and strength of radiation used

  • Tumor type

  • Where the tumor is

Short-term side effects can include:

  • Brain swelling

  • Fatigue

  • Nausea

  • Vomiting

  • Infection

  • Dizziness

  • Headache

  • Seizures

  • Hair loss

  • Hearing loss

  • Skin changes in the treated area

Long-term side effects can include:

  • Memory loss

  • Trouble thinking

  • Permanent hair loss

  • Hormonal changes

  • Death of nearby tissue (necrosis)