Radiotherapy treats cancer by using high-energy rays which destroy the cancer cells, while doing as little harm as possible to normal cells.

Radiotherapy only treats the area of the body it is aimed at and so may be used when the lymphoma cells are contained in one or two areas of lymph nodes in the same part of the body (stages 1 or 2). It may be given in addition to chemotherapy.

The treatment is given in the hospital radiotherapy department, usually as daily sessions from Monday to Friday, with a rest at the weekend. The length of your treatment will depend on the type and stage of the lymphoma, but is normally about four weeks.

To make sure the radiotherapy is as effective as possible, it has to be carefully planned.

On your first visit to the radiotherapy department you will be asked to lie under a large machine called a simulator, which takes x-rays of the area to be treated. Sometimes a CT scanner is used for the same purpose. Treatment planning is a very important part of radiotherapy and may take a few visits. The treatment is planned by a doctor: a clinical oncologist.

The radiographer, who gives you your treatment, will draw marks on your skin to help position you accurately and show where the rays are to be directed. These marks must stay visible throughout your treatment. However, they can be washed off once your treatment is over. Some people may have tiny, permanent marks (tattoos) made: these will only be done with your permission. At the beginning of your treatment you will be given instructions on how to look after your skin in the area being treated.

Before each session of radiotherapy the radiographer will position you carefully on the couch and make sure that you are comfortable. During your treatment, which only takes a few minutes, you will be left alone in the room but you will be able to talk to the radiographer who will watch you from the next room. Radiotherapy is not painful but you have to lie still for a few minutes while your treatment is being given.

A course of radiotherapy will nearly always cause tiredness. Other side effects you have will depend on the part of your body being treated. Any treatment to the abdomen can cause stomach upsets such as feeling sick (nausea), vomiting or diarrhoea. Treatment to the head can cause hair loss. Radiotherapy to the neck can make your mouth, or throat, sore. You may also notice that some foods taste different from normal. These side effects can be mild or more troublesome, depending on the length of your treatment.

Your radiotherapist will be able to advise you what to expect. They can prescribe medicines to help with side effects such as sickness or diarrhoea. Our section on eating problems has helpful tips on coping with eating problems caused by treatment. Your radiotherapist will be able to advise you what to expect. We also have information about coping with specific side effects, such as a dry mouth.

Radiotherapy can have long-term (permanent) side effects. These are rare and again, will vary depending on the part of the body treated. You can ask your specialist if you are concerned about long-term side effects.

Tiredness

As radiotherapy can make you tired, you should try to get as much rest as you can, especially if you have to travel a long way for treatment each day. Fatigue syndrome is a term often used to describe the tiredness that can occur during and after treatment. It generally begins in the latter half of treatment and can continue for several months or even years after treatment has finished. Balancing rest and activity throughout the day is important as your body needs rest to recover from the treatment.

Feeling sick (nausea)

Nausea can usually be effectively treated by anti-emetics (anti-sickness drugs), which your doctor can prescribe. If you don't feel like eating, you can replace meals with nutritious high-calorie drinks which are available from most chemists. We have information on managing nausea and vomiting.

Hair loss

Although radiotherapy can cause hair loss, this only occurs in the area being treated. For example, if you have radiotherapy to the lymph nodes in your neck, you may lose the hair on the back of the neck. Radiotherapy to the nodes in the chest may make the hair on your chest fall out.

When you have finished the course of treatment, your hair will usually grow back. It normally takes between six and twelve months, depending on the dose of radiotherapy and the length of treatment.

All these side effects will disappear gradually once your course of treatment is over. Let your doctor know if they continue.

Radiotherapy does not make you radioactive and it is perfectly safe for you to be with other people, including children, throughout your treatment.

Our section on radiotherapy discusses this treatment in more detail.