Radiotherapy uses high energy rays to kill cancer cells. It may be used when there are Hodgkin's cells in one or two areas of lymph nodes in one part of the body (stage 1 or 2). Or it may be given along with chemotherapy to areas with a lot of disease.

You have radiotherapy in the hospital radiotherapy department. Usually, you have treatment once a day from Monday to Friday, with a rest over the weekend. The length of the treatment will depend on the area you are having treated.
On your first visit, you will lie under a machine called a simulator. The doctor uses it to work out where to give the treatment. He or she will make marks on your skin, to help line up the radiotherapy machine when you have your treatment. The actual treatment only takes a few minutes. Radiotherapy does not make you radioactive.

The commonest general side effects are reddening of the skin in the treatment area, tiredness, and loss of hair in the treatment area. If your abdomen is being treated, you may feel sick or have diarrhoea.
Most people don't have serious long term effects. The commonest long term effect is changes to the skin colour. Rarer long term problems include the risk of a second cancer, heart problems, changes to your thyroid gland, infertility and inflammation of the lungs.