Brachytherapy: The Basics
Radiation therapy can be given to treat some cases of cancer. It can be given either externally (outside the body) or internally (inside the body). Patients can receive one type or both types together. Radiation given internally is called brachytherapy.
What is brachytherapy?
Brachytherapy is a type of radiation therapy that is given inside the body. Radioactive material is put into the body, as close as possible to the cancer. The tissues surrounding the radioactive material receive the most radiation. As you get further away, the radiation received becomes less. This results in less damage to healthy tissues in the area of the cancer, compared to external beam radiation. Brachytherapy also delivers a higher dose of radiation in a shorter period of time, compared to external beam radiation.
What type of cancer is brachytherapy used to treat?
This form of radiation can be used for:
- Cancers of the uterus, cervix, and vagina.
- Prostate cancer.
- Head and neck cancer.
- Breast cancer.
- Lung cancer.
- Thyroid cancer.
- Cancers of the eye.
- Some gastrointestinal cancers.
Are there different types of brachytherapy?
There are a number of radioactive materials that can be used to give brachytherapy treatments. These include radium, cesium, iridium, iodine, phosphorus, or palladium. In most cases, the radioactive substance is "sealed" in small containers (such as seeds, pellets, thin wires, or tubes).
How is brachytherapy given?
Radiation can be put into a body cavity, such as a windpipe in the lung or a woman’s vagina. This is called intracavity brachytherapy. Interstitial brachytherapy involves putting the radiation into tissue, such as the prostate gland. In some cases, the radioactive substance is "unsealed" and is taken by mouth or injected into the bloodstream, where it travels to the cancer.
Sometimes the radiation is put in the body in the operating room, during a surgery or endoscopy procedure. In other cases, an “applicator” is placed where the radiation is needed. The applicator contains no radioactivity, but radioactive material will be placed in the applicator at a later time. The care team may use radiology tests, such as CT scan and ultrasound to guide the placement of the applicator.
High Dose Rate Versus Low Dose Rate
Brachytherapy can be given in several ways:
- High dose rate: The radioactive material is put into your body for a short time. The amount of time is based on the dose of radiation needed. This can be a little as a few minutes or up to 20 minutes. The radioactive material is then removed, and you can go home. If the catheter or applicator being used for your treatment needs to stay in place then you will need to stay in the hospital until the end of your scheduled treatments. You are not radioactive after the radioactive material is removed.
- Low dose rate: The radioactive material is put into your body and releases a low dose of radiation over a period of several hours to days. In many cases, this is done during a stay in the hospital. While the material is in your body, you are putting off radiation, so there are strict restrictions on visitors to your room. Once the dose of radiation has been received, the radioactive material is removed from your body. Once it is removed, you are safe to have visitors and will likely be sent home.
- Permanent brachytherapy: This is a type of low dose rate therapy. It is often used in treating prostate cancer. The radioactive material is put into your body and left there. The radioactive material used will “decay” over time – or stop putting off radiation after a period of time. You may need to follow restrictions to protect those around you for a period of time. Your team will give you instructions if this is necessary.
Radioactive iodine (I-131) is an “unsealed” radioactive source for treating thyroid cancer. I-131 is taken in a pill form and travels through the body. The iodine causes the compound to go directly to the thyroid cells. This brings the radiation right to the cancer cells.
For 1-2 days after treatment, radiation leaves the patient’s body in their stool, urine, saliva and perspiration. The patient is “radioactive” for a period of time after treatment. Patients and caregivers are given detailed instructions to keep those around them safe from radiation exposure.
You can learn more about brachytherapy in the following articles:
American Thyroid Association (ATA) Guidelines Taskforce on Thyroid Nodules and Differentiated Thyroid Cancer, Cooper, D. S., Doherty, G. M., Haugen, B. R., Kloos, R. T., Lee, S. L., et al. (2009). Revised American Thyroid Association management guidelines for patients with thyroid nodules and differentiated thyroid cancer. Thyroid : 19(11), 1167-1214.
American Thyroid Association Taskforce On Radioiodine Safety, Sisson, J. C., Freitas, J., McDougall, I. R., Dauer, L. T., Hurley, J. R., et al. (2011). Radiation safety in the treatment of patients with thyroid diseases by radioiodine 131I : Practice recommendations of the American thyroid association. Thyroid :, 21(4), 335-346.
National Cancer Institute. Brachytherapy to Treat Cancer. 2019.
RadiologyInfo.org. Brachytherapy. 2019.