• Radiotherapy (X-ray treatment) can be used as either the main treatment for some cancers, or in addition to surgery and chemotherapy. It can also be used to treat cancer that has returned after treatment.

• A radiotherapist will first assess the area that needs radiotherapy, which is called the 'field', and calculate the dose and number of visits that you need.

• The two main types of radiotherapy are called external- beam radiotherapy and brachytherapy. With external- beam radiotherapy, an X-ray beam is directed at the area with the cancer, while brachytherapy involves leaving an X-ray-emitting device in the uterus or vagina. This is usually inserted under a general anaesthetic, and it may be left in place for up to a day, depending on the type of device used.

• You may have skin rashes, diarrhoea, bladder irritation, tiredness and flu-like symptoms during and straight after treatment. Many of these can be relieved with medical treatments, although bladder or bowel irritation may persist for months or become permanent. In young women, the ovaries may stop making hormones, and hormone-replacement therapy (HRT) may be needed on a long-term basis.

• A very uncommon but serious possible side-effect is fistula formation, where an opening forms between either the bowel or urinary system and the vagina. An operation is usually required to overcome this problem.