by EBSCO Medical Review Board
(Ionizing Radiation; Radiotherapy; Brachytherapy)


Radiation therapy (RT) treats cancer and other diseases. It uses high-energy particles. These break the DNA in the cancer cells. The cells can’t grow or split after RT.

There are 2 main types of RT:

  • External — A machine sends radiation. It aims it at cells from outside the body.
  • Internal— Radioactive materials are placed in the body near the cells.

You doctor may want to use both. Surgery, chemotherapy , and therapy to spark the immune system to fight infection may also be used.

This fact sheet will focus on internal RT.

Reasons for Procedure

The doctor may use RT to:

  • Control the growth or spread of cancer
  • Try to cure your cancer
  • Reduce pain or other cancer symptoms

RT treats solid tumors, such as:

Possible Complications

Internal RT does not cause your body to become radioactive. It can cause side effects. The RT harms healthy cells and cancer cells.

Here are some problems you may have:

  • Feeling very tired
  • Skin changes such as redness and irritation
  • Reduced white blood cell count
  • Hair loss
  • Nausea, vomiting, or diarrhea
  • Lack of hunger

Talk to your doctor about the problems you may have.

Other things that may raise the risk of problems are:

You should not be around radiation if you are pregnant or could be pregnant. It could harm the growing fetus.

What to Expect

Prior to Procedure


You may need:

Description of the Procedure

The doctor will put the radiation source on or near the problem site in your body. This gives you higher doses in a shorter time. The sources are in the form of wires, seeds, or rods. This method is for cancers of the:

The 2 main types of internal RT are:

  • Interstitial—Rods, ribbons, or wires placed inside the problem site on a short-term or permanent basis.
  • Intracavitary—Radioactive material is placed inside a body space on a short-term basis. Examples of spaces are the uterus, vagina, or windpipe.
Rods for Internal Radiation
brachtherapy seeds
Copyright © Nucleus Medical Media, Inc.

How Long Will It Take?

The time it takes varies. Your cancer type and method of internal RT play a role.

Will It Hurt?

Anesthesia prevents pain. You may be sore after. It depends on where the material was placed.

Average Hospital Stay

You will stay in the hospital until the doctor takes the implant out. If you had a permanent one, you will stay until the radioactivity is lower. The doctor takes out high-dose ones in minutes. Low-dose ones may stay in for a few days. Permanent ones lose their effect within a few days.

You will return to a room while the implant is in place. You will follow these safety steps:

  • Limited visitation: Children under 18 years old and pregnant women may not be able to visit you. They may visit after the doctor takes the implant out. If you can have visitors, they will need to sit at least 6 feet from the bed. Visits will be 10-30 minutes. Staff may place a shield beside the bed to protect others.
  • Limited contact with the staff: The staff will be there for you at all times. They may speak to you from the doorway. They may also come and go quickly so they are not around the radiation for too long.

Post-procedure Care

Your doctor will want to see you at least once a week. You may have routine blood tests to check on your progress.

After RT is done, you will have fixed visits. The doctor will check your healing and make sure the RT worked. Care may also mean more testing, medicines, or rehabilitation.

Call Your Doctor

Call your doctor if you have:

  • Signs of infection, such as fever and chills
  • Diarrhea or loss of hunger
  • Weight loss without a known cause
  • Frequent urination
  • Pain or burning with urination
  • New or unusual swelling or lumps
  • Nausea and vomiting
  • Pain that doesn't go away with the medicines you were given
  • Changes in skin, such as bruises, rashes, discharge, or bleeding
  • Cough, problems breathing, or chest pain
  • New or unexpected symptoms

If you think you have an emergency, call for emergency medical services right away.


American Cancer Society 

Radiology Info—Radiological Society of North America 


Canadian Association of Radiologists 

Canadian Cancer Society 


Bracytherapy. Radiological Society of North America Radiology Info website. Available at: Accessed January 28, 2021.

Radiation. Oncolink, University of Pennsylvania Cancer Center website. Available at: Accessed January 28, 2021.

Radiation therapy. American Cancer Society website. Available at: Accessed January 28, 2021.

Radiation therapy for cancer. National Cancer Institute website. Available at: Accessed January 28, 2021.

Revision Information