Radiation Therapy—Internal

(Ionizing Radiation; Radiotherapy; Brachytherapy)


Radiation therapy is used to treat cancer and other diseases. It uses high-energy particles to damage the DNA in the cancer cells. This makes the cells unable to grow or divide.

There are 2 main types of radiation therapy:

  • External—radiation is delivered by a machine that shoots particles at the cells from outside the body
  • Internal—radioactive materials are placed in the body near the cancer cells; this is also called implant radiation or brachytherapy

In certain cases, your doctor may recommend a combination of these. Radiation is often used with other types of treatment, such as surgery, chemotherapy, and immunotherapy, which stimulates the immune system to fight infection.

This fact sheet will focus on internal radiation therapy.

Reasons for Procedure    TOP

This procedure is done to:

  • Control the growth or spread of cancer
  • Attempt to cure cancer
  • Reduce pain or other symptoms caused by cancer—palliative radiation

Radiation therapy is used to treat solid tumors, such as prostate cancer, breast cancer, and head and neck cancers.

Possible Complications    TOP

Internal radiation can cause side effects. The radiation damages your own healthy cells as well as the cancer cells. The side effects will vary depending on the type and location of treatment. Common side effects of radiation include, but are not limited, to:

  • Fatigue
  • Skin changes such as redness and irritation
  • Reduced white blood cell count
  • Hair loss
  • Nausea, vomiting, or diarrhea
  • Appetite loss

Discuss the specific side effects that you may have with your doctor.

Factors that may increase the risk of complications include:

A woman who is pregnant or could be pregnant should avoid exposure to radiation. It could harm a developing fetus.

What to Expect    TOP

Prior to Procedure


You may need local anesthesia, which will numb a small area, or general anesthesia, which keeps you asleep during the procedure.

Description of the Procedure

The radiation source will be placed inside your body on or near the affected area. This provides higher doses of radiation in a shorter time. The radioactive sources are in the form of wires, seeds, or rods. This treatment is mostly used for cancers of the head and neck, breast, uterus, thyroid, cervix, and prostate. The 2 main types of internal radiation are:

  • Interstitial radiation—Rods, ribbons, or wires placed inside the affected tissue on a short-term or permanent basis.
  • Intracavitary radiation—A container of radioactive material is temporarily placed inside a body cavity, such as the uterus, vagina, or windpipe.

Rods for Internal Radiation

brachtherapy seeds
Copyright © Nucleus Medical Media, Inc.

How Long Will It Take?    TOP

How long it will take depends on the type of cancer treated and the method of internal radiation

Will It Hurt?    TOP

Anesthesia prevents pain during the procedure. You may be sore when recovering from the procedure depending on where the radioactive material was placed.

Average Hospital Stay    TOP

You will stay in the hospital until the implant is removed, or in the case of a permanent implant, when the radioactivity has decreased. High-dosage implants are usually removed within a matter of minutes. Low-dosage implants may stay in for a few days. Permanent implants lose their radioactivity within a few days.

You will return to a hospital room while the implant is in place. While the radiation is implanted, you will follow these precautions to prevent transmitting radiation to others:

  • Limited visitation: Many hospitals do not allow children under 18 years old or pregnant women to visit a patient having implant radiation. They may visit after the implant is removed. If visitors are allowed, they will need to sit at least 6 feet from the bed. Visits will be limited to 10-30 minutes. Staff may place a shield beside the bed to protect visitors and staff from radiation exposure.
  • Limited contact with the staff: The staff will be available to you at all times. They may speak to you from the doorway. They may also come and go quickly to avoid excessive radiation exposure.

Post-procedure Care    TOP

During treatment, your doctor will want to see you at least once a week. You may have routine blood tests to check for the effects of radiation on your blood cells.

After treatment is completed, you will have regular visits to monitor healing and to make sure the treatment affected the disease as planned. Follow-up care will vary for each person. Care may include further testing, medication, or rehabilitative treatment.

Call Your Doctor    TOP

Call your doctor if any of these occur:

  • Signs of infection, including fever and chills
  • Diarrhea or loss of appetite
  • Unexplained weight loss
  • Frequent urination, particularly if it is associated with pain or burning sensation
  • New or unusual swelling or lumps
  • Persistent nausea or vomiting
  • Pain that does not go away with the medications you were given
  • Unusual changes in skin, including bruises, rashes, discharge, or bleeding
  • Cough, shortness of breath, or chest pain
  • Any other symptom your nurse or doctor told you to look for
  • Any 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: https://www.radiologyinfo.org/en/info.cfm?pg=brachy. Updated May 8, 2017. Accessed March 29, 2018.
Radiation. Oncolink, University of Pennsylvania Cancer Center website. Available at: https://www.oncolink.org/cancer-treatment/radiation. Accessed March 29, 2018.
Radiation therapy. American Cancer Society website. Available at: https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/radiation.html. Accessed March 29, 2018.
Radiation therapy for cancer. National Cancer Institute website. Available at: https://www.cancer.gov/about-cancer/treatment/types/radiation-therapy/radiation-fact-sheet. Accessed March 29, 2018.
Last reviewed March 2018 by EBSCO Medical Review Board Mohei Abouzied, MD, FACP
Last Updated: 3/18/2013

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