Radiotherapy is the most commonly used treatment for patients with localised prostate cancer in the UK. It works by damaging a cell’s deoxyribonucleic acid (DNA) so that it can no longer survive. External beam radiotherapy uses linear accelerators to deliver small daily fractions of radiotherapy to the prostate gland. In brachytherapy, radioactive sources are implanted into the prostate gland.

Stereotactic ablative body radiotherapy is a method of delivering precise radiotherapy in fewer, higher dose fractions than conventional radiotherapy. The main short-term side effects of prostate radiotherapy include dysuria, urinary retention or diarrhoea. In the longer term, a minority of patients have difficulties with urinary or faecal urgency or incontinence or rectal bleeding. Fatigue can also have a significant effect on patients’ quality of life during and after treatment. Newer methods of delivering radiotherapy such as intensity modulated and stereotactic ablative body radiotherapy have been developed to deliver the maximum dose to the tumour while reducing side effects.