This type of internal radiotherapy treatment is used for treating cancer of the cervix, womb (uterus) or vagina. A piece of radioactive metal, known as a source, is put close to the area of the cancer. The metal most commonly used is caesium-137. The advantage of treatment with caesium is that it gives a high dose of radiotherapy directly to the tumour, but a low dose to normal tissues.

The caesium is put inside a hollow, plastic tube known as an applicator. Sometimes more than one tube is used. This keeps the caesium in place. The applicator is inserted into the vagina while you are under a general anaesthetic or sedation in the operating room. At the same time, a flexible tube called a urinary catheter may be put into your bladder to drain off urine. This means you will not have to get on and off bedpans, which could dislodge the applicators.

Once the applicator is in place, an x-ray will be taken to check it is in the correct position. Sometimes the radioactive source is put into the applicator while you are in the operating room, but more commonly it will be put in place once you are back on the ward. The applicator is kept in place by a pack (cotton/gauze padding) inside your vagina. This can be uncomfortable and you may need to ask your nurses for regular painkillers.

Once the source is put into the applicators you have to stay in bed, so that the applicator does not move out of position. If you need anything, you can call a member of staff by using the buzzer by your bed. If the source does move out of position, you should call the staff on the ward immediately.

In many hospitals a machine called a Selectron, or similar name, is used to put the radioactive material into the applicators. The machine is attached by tubes to the applicators. When the machine is switched on, it passes small radioactive balls into the applicators. If the machine is switched off, the radioactive balls are pulled back inside the machine.

The machine is kept switched on throughout treatment, except when someone needs to go into your room. It can then be turned off, to reduce their exposure to the rays. However, safety measures and visiting restrictions are still necessary. The time you spend on the machine varies, but it is usually between 12–48 hours.

Sometimes a machine called a Microselectron is used for internal radiotherapy. It gives the radiotherapy more quickly, so the treatments last for only a few minutes and you can go home the same day.

Once the complete radiation dose has been given, the source and the applicators will be removed. This is usually done on the ward. As it can be a little uncomfortable, you will be offered some painkillers beforehand. Sometimes a few breaths of the gas Entonox will help you to relax. Staff on the ward will check that all the applicators and sources have been removed. Your catheter may be removed at the same time.

Your specialist may suggest that you use vaginal douches for a few days after the applicator has been removed to keep the vagina clean. Your nurse will tell you how to use these.

You will probably be able to go home the same day, or the following day. Once the radioactive sources are removed, all traces of radioactivity immediately disappear.

Many women are given both internal and external radiotherapy to ensure the cancer is treated in the most effective way.

It is not unusual to have slight bleeding or discharge once the radiotherapy treatment has ended. If it continues or becomes heavy it is important to let your doctor or nurse know.

Radiotherapy to the pelvic area can cause side effects such as tiredness, diarrhoea and a burning sensation when passing urine. These side effects can be mild or more troublesome depending on the strength of the radiotherapy dose and the length of your treatment. Your oncologist will be able to advise you what to expect.

Most of these side effects can be treated with medicines, which your oncologist can give to you. Any side effects should gradually disappear once your treatment is over.

It is important that you drink plenty of fluids and maintain a healthy diet during your treatment. If you have diarrhoea you can ask your doctor to prescribe anti-diarrhoea medicines. You may feel sick but this is not common. If you don't feel like eating, you can replace meals with nutritious high-calorie drinks, which are available from most chemists and can be prescribed by your GP. Our section on eating well has some helpful tips on eating when you are feeling ill.

Unfortunately, radiotherapy for cancer of the cervix affects the ovaries, and brings on the menopause, usually about three months after the treatment starts. This means that your periods will stop and you will have menopausal side effects such as hot flushes, dry skin and possibly loss of concentration. Some women become less interested in sex and notice that their vagina is dry. Sometimes radiotherapy causes a narrowing of the vagina, which can make sexual intercourse uncomfortable. See our sections sexuality and fertility for advice on how to deal with the effects on your sex life and fertility.

You can be protected from menopausal side effects by taking HRT (hormone replacement therapy) as tablets or skin patches. Your gynaecologist may start you on these during the radiotherapy treatment or shortly after it has ended.

It is important to get as much rest as you can, especially if you have to travel a long way for treatment each day.

Radiotherapy to the pelvic area can sometimes cause long-term side effects. However, improvements in treatment planning have made these much less likely.

In a small number of people, the bowel or bladder may be permanently affected by the radiotherapy. If this happens the increased bowel motions and diarrhoea may continue, or the person may need to pass urine more often than before. The blood vessels in the bowel and bladder can become more fragile after radiotherapy treatment and this can make blood appear in the urine or bowel movements. This can take many months or even years to occur.

If you notice any bleeding it is important to let your doctor know so that tests can be done and appropriate treatment given.

Our section on pelvic radiotherapy in women has tips on coping with these side effects.

Some people also find that radiotherapy affects the lymph glands in the pelvic area and can cause swelling of the legs. This is known as lymphoedema. It is more likely if you have had surgery as well as radiotherapy.

After caesium brachytherapy there is a slight risk of infection, but this is very rare. If you develop a high temperature or heavy bleeding after your treatment, contact your specialist as soon as possible. You will be prescribed antibiotics to treat the infection.

These can be used to treat a number of types of tumours including those in the mouth, lip, cervix and breast. Very thin radioactive needles, wires or tubes are inserted while you are under general anaesthetic in the operating room.

An x-ray may be taken to ensure that the needles are in the correct position. You will be nursed in a separate room, and safety measures will be used until the wires are removed – usually after three to eight days. Sometimes this is done under general anaesthetic.

Wires in the mouth can be uncomfortable, and can make eating and talking difficult. You will need to have a soft or liquid diet while they are in place. Your nurse will show you how to keep your mouth clean, using regular mouthwashes. If eating is a problem you may be fed through a thin tube (a nasogastric tube), passed up your nose and down into your stomach.

The wires are removed once the correct dose of radiation has been given. This may be after two days if the treatment is given as a booster following external treatment, or up to one week if it is the only type of radiotherapy treatment being given.

Once the wires have been removed, the area will feel sore for up to two or three weeks afterwards. Your specialist will prescribe painkillers that you can take regularly until this improves.

Brachytherapy (radioactive seed implants) is sometimes used to treat small tumours of the prostate gland.

Brachytherapy is available in some hospitals in the UK. It is carried out under a general anaesthetic, or sometimes a spinal anaesthetic. Small radioactive metal seeds are inserted into the tumour within the prostate gland, and they release small doses of radiation very slowly over a period of time. The seeds are not removed, but stay in the prostate tissue. The radioactivity gradually fades away over approximately a year. The radiation affects only the area a few millimetres around the seeds, so there is no danger of it affecting other people.

Side effects

It is fairly common to feel some soreness and bruising after the seeds are implanted. Your doctor can prescribe painkillers to help.

Some men get blood in their urine, which is quite normal. If you notice a lot of blood you should let your doctor know. It can help to drink plenty of fluids to flush through any blood.

It may be painful to pass urine for a time, or you may need to pass urine more frequently, or have a weaker stream. Up to one in seven men will have difficulty passing urine after brachytherapy. Some men will need a catheter inserted for a while. Occasionally the tube that drains urine from the bladder (urethra) will narrow some time later. If this happens, the urethra can often be stretched.

Brachytherapy treatment may cause impotence, and some men may become infertile after treatment.

Our section on early (localised) prostate cancer explains this treatment in more detail. See also our information about the possible late effects of pelvic radiotherapy.