What is internal radiotherapy?

Internal radiotherapy gives radiation from inside the body. It is also known as brachytherapy. A small radioactive material called a source is put into your body, inside or close to the cancer. Or into the area where the cancer used to be before having surgery.

There are different types of radioactive sources which are also called implants. These are seeds, wires or discs. They deliver radiotherapy to the area, destroying the cancer cells. Healthy tissue near to the cancer gets a lot less radiation.  

Your doctor works out how much radiation you need. This affects how long the radioactive source stays inside you for. This can be anything from several minutes to a few days, or can stay in place permanently. If the source stays inside you permanently, it stops giving off radiation after a few weeks or months.

Radioisotope therapy

You may have also heard of radioisotope therapy. This uses radioactive medicines to treat some types of cancer. It is also known as radionuclide therapy. This is sometimes called internal radiotherapy.

Types of brachytherapy

The way you have brachytherapy varies depending on the type of cancer you have. But there are 2 main types:

• High dose rate (HDR) brachytherapy
• Low dose rate (LDR) brachytherapy

High dose rate brachytherapy

With high dose rate brachytherapy, the radioactive source is in your body for several minutes. The radioactive source travels from the brachytherapy machine through hollow tubes or needles. These are called applicators. The source passes through these to get to the right position. You may have the applicators put in while under general anaesthetic.

After 5 to 20 minutes of treatment, the source travels back along the applicators to the brachytherapy machine. You are no longer radioactive.

You might have:

• a single treatment
• several treatments over a number of days

Sometimes you have two treatments on one day.

The applicators might be put in before each treatment session. Or stay in place until after your final treatment. Your treatment team will give you information about what to expect before treatment starts.

Low dose rate brachytherapy

With low dose rate brachytherapy, you have a lower dose of radiation over a longer time. You might have the radioactive source in place for up to a week. You stay in hospital during this time, in a room on your own. After treatment, your doctor removes the radioactive source and you can go home. Once the source is take away you are no longer radioactive. 

Permanent seed brachytherapy is a type of low dose rate brachytherapy for prostate cancer. The radioactive source is in the form of tiny metal seeds that stay in the prostate forever. The seeds slowly give off radiation over a few months. You can be at home after having the seeds put in. You are slightly radioactive for some time sp you have to avoid very close contact with children and pregnant women. Your treatment team will give you clear instructions to follow.

Planning brachytherapy

To plan your brachytherapy, you have a scan, such as a CT or an ultrasound scan. Your doctor uses the scans to work out how much radiation you need and where to put the radioactive source.

When you might have brachytherapy

Doctors mainly use brachytherapy for cancer of the:

• prostate
• cervix
• womb
• vagina

They might also use it for other cancers, such as cancer of the eye, back passage (rectum), penis or breast.

Brachytherapy might be the only type of radiotherapy you have. Or you might have it with external radiotherapy.

Prostate brachytherapy

You might have brachytherapy for prostate cancer. This means a radioactive source is put inside the prostate. The radioactive source releases radiation to destroy the prostate cancer cells.

The source, also known as radioactive seeds, might stay inside your prostate permanently. This is called low dose rate brachytherapy. The radiation is gradually released over a number of months.

Or you might have a higher dose of radiation.  The radioactive source stays inside the prostate for about 15 to 40 minutes. This is called high dose rate brachytherapy. Your radiographers then remove the source and so you have no radiation left inside your body.

Brachytherapy to the cervix, womb or vagina  

You might have brachytherapy for cancer of the cervix, womb or vagina.

Your doctor puts hollow tubes into the vagina to the area where the cancer is. This happens under general anaesthetic. They attach the tubes to a brachytherapy machine. The radioactive source moves from the machine through the tubes to the cancer.

The radioactive source may stay inside your body for about 10 to 20 minutes.  After the treatment, the source moves back into the machine. You may have several treatments. You have this treatment as an inpatient or outpatient.

Brachytherapy for other cancer types

There are some different types of brachytherapy for other cancer types.

For eye cancer, you have a small radioactive metal disc placed over the cancer on the eye. This disc is called a plaque. The plaque continually gives off radiation while it is in place and it treats a small area. You have this treatment as an inpatient over 2 to 7 days.

Brachytherapy to the breast might mean you stay in hospital for a few days. You have thin hollow tubes or a small balloon put into your breast. Your radiographers connect the tubes or balloon to the brachytherapy machine. A radioactive pellet travels from the machine into the tubes or balloon to treat the nearby area. The radioactive source stays in place for a few days, or for several minutes once or twice a day for a few days.

Doctors may use a type of brachytherapy called selective internal radiation therapy (SIRT) for bowel cancer that has spread to the liver (liver metastases). They put tiny radioactive beads into a blood vessel that takes blood into your liver. The beads get stuck in the small blood vessels in and around the cancer. And the radiation destroys the cancer cells. Although the beads stay in place forever, the radiation is released over a couple of weeks.

The range of radiation from the beads is very small. But as a precaution, you might be told to avoid close contact with young children and pregnant women for the first week or so after treatment. Your doctor might also advise you not to share a bed with your partner for the first night or two.

To find out about brachytherapy for other types of cancer, go to the treatment section of your cancer type.

Safety precautions

When the radioactive source is in your body you will give off some radioactivity. To protect others from exposure to radiation you may need to follow certain safety precautions.

You have brachytherapy treatment in a room on your own. And if you’re staying as an inpatient you may need to limit visitors. Pregnant women and children may not be allowed to visit. Once they remove the source from your body you are no longer radioactive and can be with other people.

With permanent brachytherapy, the radiation gradually fades over weeks or months. The radiation doesn’t travel much further than the treatment area. But as a precaution your team may tell you to avoid very close contact with pregnant women and children during this time.

Side effects

The side effects that you may get from brachytherapy depend on which part of the body you’re having treatment to. Brachytherapy treats a small area close to the cancer therefore it affects fewer healthy cells. The side effects are often less than they would be if you were having external radiotherapy.

The most common side effects often happen shortly after having treatment and may last for a couple of weeks. There is a risk of late side effects that happen months or years after having treatment.

Your treatment team go through all the possible side effects before you start treatment. Tell them if you develop any side effects so that they can help you manage them.