Systemic Radiation Therapy

Radioactive drugs (called radiopharmaceuticals) are used to treat certain types of cancer systemically. These drugs can be given by mouth or put into a vein; they then travel throughout the body. You may need to be in the hospital for 1 or 2 days while getting this treatment, called systemic radiation therapy.

What is systemic radiation therapy?

Certain cancers, such as thyroid, bone, and prostate are treated with radiopharmaceuticals (radioactive drugs) . A radiopharmaceutical is a liquid drug made up of a radioactive substance. It is sometimes bound to a special antibody (called a monoclonal antibody) that attaches to the cancer cells. Examples of radiopharmaceuticals used for systemic radiation include radioactive iodine, strontium, samarium, and radium.

These drugs may be given in a vein (IV) or taken by mouth. They travel in the blood throughout the body. The antibody makes them attach to the cancer cells. They then give off their radiation and kill the cancer cells.

Will I be radioactive during or after systemic radiation treatment?

Because systemic radiation uses an unsealed radioactive substance that goes through your whole body, some radiation will be in your body for a few days until your body has had a chance to get rid of it. You may need to stay in the hospital for 1 or 2 days.

To protect others from radiation, the drugs are kept in special containers that hold the radiation inside, and you’ll be treated in a shielded room that also keeps the radiation inside. The health providers handling the drugs might wear safety gear that protects them from exposure while giving you the radioactive drug.

Patient and family safety

Sometimes safety measures are needed to protect the people around you from the systemic radiation in your body. This is because the radioactive materials can leave your body through saliva, sweat, blood, and urine and that makes these fluids radioactive.

Your cancer care team will tell you what precautions to take until your body no longer contains radiation that might affect others. What you will need to do depends on the substance used.

In most cases, the safety precautions must be followed only the first few days after treatment. Over time, the radiation becomes weaker and your body gets rid of it. Talk to your cancer care team about how long this may take in your case, and if there are special precautions you will need to take.

You might be told to follow these steps for a certain amount of time:

  • Flush the toilet twice after each use, and wash your hands well after using the toilet.
  • Use separate utensils and towels (laundry may need to be washed separately).
  • Drink extra fluids to flush the radioactive material out of your body.
  • No kissing or sexual contact (often for at least a week).
  • Keep a distance of one arm’s length between yourself and any others who spend more than 2 hours next to you in any 24-hour period. (You may need to sleep alone for a week or so.)
  • Limit your contact with infants, children, and women who are pregnant.
  • Limit your contact with pets.

Be sure you understand what you need to do to protect the people around you. 

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Halperin EC, Perez CA, Brady LW (Eds). Principles and Practice of Radiation Oncology. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2013.

Hogle WP. Cytoprotective Agents Used in the Treatment of Patients With Cancer. Sem in Onc Nsg. 2007;23(3):213-224.

Last Medical Review: February 10, 2017 Last Revised: February 10, 2017

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