Internal Radiation (Brachytherapy)

Brachytherapy is a type of internal radiation therapy. Instead of aiming radiation from a machine outside your body, brachytherapy places the radiation source inside you — as seeds, ribbons, or capsules put in or near the tumor.

It is a local treatment, so it treats only a specific part of your body. It is often used for cancers of the head and neck, breast, cervix, prostate, and eye.

With brachytherapy, the radiation comes from a source placed inside your body, close to the cancer.

You will have a 1- to 2-hour meeting with your doctor or nurse to plan your treatment. You will have a physical exam, talk about your medical history, and maybe have imaging tests. Your doctor will discuss which type of brachytherapy is best for you, its benefits and side effects, and how to care for yourself. You can then decide whether to have it.

Most brachytherapy is put in place through a catheter, which is a small, stretchy tube. Sometimes a larger device called an applicator is used instead. Your doctor places the catheter or applicator into your body before treatment begins.

There are several techniques, depending on your cancer:

• Interstitial brachytherapy places the source within the tumor itself, as with prostate cancer.
• Intracavity brachytherapy places the source within a body cavity, such as the vagina to treat cervical or endometrial cancer.
• Episcleral brachytherapy attaches the source to the eye, used for melanoma of the eye.
• Radioembolization places tiny radioactive beads into the main blood vessel that carries blood to the liver, used for liver cancer or cancer that has spread there.

Once the catheter or applicator is in place, the radiation source is placed inside it. How long it stays depends on the type of source, your cancer, where it is, your health, and other treatments you have had.

Low-dose rate (LDR) implants. The radiation source stays in place for 1 to 7 days. You are likely to be in the hospital during this time. When treatment is finished, your doctor removes the source and the catheter or applicator.

High-dose rate (HDR) implants. The source is left in place 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, depending on your cancer. The catheter may stay in place or be put in before each treatment.

Permanent implants. After the source is put in place, the catheter is removed. The implants stay in your body for life, but the radiation gets weaker each day until almost all of it goes away. When the radiation is first placed, you may need to limit your time around others and take safety measures — especially being extra careful around children and pregnant women.

Once you finish LDR or HDR treatment, the catheter is removed. Here is what to expect:

• You will get medicine for pain before it is removed.
• The area may be tender for a few months.
• There is no radiation in your body after removal, so it is safe for others to be near you, even young children and pregnant women.

For a week or two, you may need to limit activities that take a lot of effort. Ask your doctor which activities are safe.

With brachytherapy, the radiation source in your body will give off radiation for a while. If the dose is very high, you may need safety measures such as staying in a private hospital room. Hospital staff will give you all the care you need but may stand at a distance, talk from the doorway, or wear protective clothing.

Visitors may also need to follow rules, such as keeping visits short (about 30 minutes or less each day), standing by the doorway, and avoiding visits from pregnant women and children younger than one year. Your doctor or nurse will explain any safety measures to follow at home.

• Call 911 or go to an emergency department if you cannot pass urine at all, even though your bladder feels full. Go too if bleeding from the treated area soaks through padding and keeps coming.
• Contact your cancer team immediately, at whatever hour, if your temperature hits 100.4°F (38°C) or above while you are also receiving chemotherapy. The CDC calls a fever during chemotherapy a medical emergency, since it can be the first and only clue to a dangerous infection. If they cannot be reached quickly, go to an emergency department and tell staff you are in cancer treatment as soon as you arrive.
• Call your care team the same day if you reach that same temperature on brachytherapy alone, or if the implant site turns hot, puffy, or starts weeping cloudy fluid.
• Call your care team within a day or two if tenderness at the site grows week by week instead of fading, or if burning when you urinate, or rectal pain and bleeding, do not begin to settle.

Sources: National Cancer Institute: brachytherapy and American Cancer Society: radiation therapy for prostate cancer. Fever guidance: CDC: fever during cancer treatment.