External beam radiotherapy uses radiation to kill the cancer

It is suitable for men of any age and is an effective alternative to surgery

The radiation is given by a large machine while you lay on a table

You will have a series of treatments over 2-7 weeks, each taking 10-30 minutes

The treatments are not painful

Before radiotherapy you will have a planning scan (CAT scan) so the radiation can be targeted

You will have marks on your skin to accurately position the machine

The side-effects can include bladder and bowel incontinence (usually short-term)

After radiotherapy your erections will be softer or you may not have erections

Your skin may be sore for a few weeks after the radiotherapy

You may be infertile after radiotherapy

You may feel tired after radiotherapy

If your life expectancy is less than 10 years, you may be offered watchful waiting