What is brachytherapy?

Brachytherapy is internal radiation therapy that uses a solid radiation source. As the National Cancer Institute describes it, "seeds, ribbons, or capsules that contain a radiation source are placed in your body, in or near the tumor." NCI says it is a local treatment that treats only a specific part of your body, and is often used for cancers of the head and neck, breast, cervix, prostate, and eye.

How it is delivered

A catheter or applicator goes in first. NCI puts it simply: "Your doctor will place the catheter or applicator into your body before you begin treatment." Only then is the radiation source placed inside it.

NCI lists several ways it can be placed. Interstitial means the source is placed within the tumor, which is used for prostate cancer, for instance. Intracavity means it is placed within a body cavity or a cavity created by surgery, for example in the vagina to treat cervical or endometrial cancer. Other forms include a source attached to the eye for melanoma of the eye. Radioembolization is another form. In it, tiny beads that hold a radioactive substance are placed in the main blood vessel that carries blood to the liver.

Three schedules, three very different weeks

NCI describes three types. Low-dose-rate implants stay in place "for 1 to 7 days," and you are likely to be in the hospital during this time.

With high-dose-rate treatment the source is in the body "for just 10 to 20 minutes at a time and then taken out." You may have treatment "twice a day for 2 to 5 days or once a week for 2 to 5 weeks," in the hospital or through daily trips.

Permanent implants are different again. The source goes in and the catheter comes out. NCI explains that "the implants remain in your body for the rest of your life, but the radiation gets weaker each day."

The part that surprises people

You may give off radiation for a while. NCI states this directly, and it is the main way brachytherapy differs from external beam. If the dose is very high, safety measures can include staying in a private hospital room, and visits kept to about 30 minutes or less each day. NCI lists no visits from pregnant women and children younger than a year old. With permanent implants, NCI says you may need to limit your time around other people when the radiation is first put in place. It says to be extra careful not to spend time with children or pregnant women. Your team will say how long that lasts.

NCI says you get medicine for pain before the catheter or applicator is removed, and the area "might be tender for a few months" afterward. After the catheter or applicator is removed there is no radiation in your body, and NCI says it is safe for people to be near you.

If brachytherapy has been offered, a useful question for your team is which of the three schedules is planned.