In some people, such as those who have small cancers of the tongue, this type of radiotherapy may sometimes be used instead of surgery.

Internal radiotherapy (also called interstitial radiotherapy, implant therapy, or brachytherapy) involves putting a radioactive material directly into the cancer. This type of radiotherapy is given by inserting radioactive needles or wires into the cancer while you are under a general anaesthetic. Over a few days, the needles or wires give a high dose of radiotherapy directly to the tumour from the inside.

While the radioactive wires or needles are in place, low levels of radiation are given out from them. You will need to stay and be cared for in a single room in hospital for a few days, until the doctor has removed the radioactive needles or wires from your body. Visitors will be restricted and although it will be safe for your family and close friends to visit you for short periods, children and pregnant women will not be allowed to visit. This is to avoid any chance of them being exposed to even tiny amounts of radiation.

The doctors and nurses caring for you will also only be able to stay in your room for short periods at a time. This is because they may be looking after several people having internal radiotherapy treatment and they must keep their exposure to the low level of radioactivity to a minimum.

The safety measures and visiting restrictions might make you feel very isolated, frightened and depressed at a time when you might want people around you. If you have these feelings it is important that you let the staff looking after you know. It can help to take in plenty of reading material and things to keep you occupied while you are in isolation. The isolation only lasts while the radioactive implant is in place (usually 1–8 days). Once it is removed the radioactivity disappears and it is perfectly safe to be with other people.

While the needles or wires are in place, the tissues around them will become swollen. This usually settles by the time they are removed. The treated area will become sore about 5–10 days after the needles or wires have been removed and this may last for several weeks. During this time, you may find it easier to eat soft foods. See changes to eating and our diet and cancer section.

While your mouth is sore it can help to avoid:

• smoking
• drinking spirits
• eating hot or spicy foods.

Drinks like milk and water will help to keep your mouth moist. Your doctor can prescribe special mouthwashes and medicines to help to relieve the discomfort.