External beam radiotherapy for prostate cancer

External beam radiotherapy is a common treatment for prostate cancer. It uses high energy waves similar to x-rays to destroy cancer cells.

External radiotherapy uses a machine outside the body to direct radiation beams at the cancer. Your doctor may suggest you have external radiotherapy in combination with hormone therapy. 

You may also have both external radiotherapy and internal radiotherapy. Internal radiotherapy gives radiation to the cancer from inside the prostate gland. 

Planning radiotherapy for prostate cancer

Your radiotherapy team needs to plan your external radiotherapy before you start treatment. This means working out the dose of radiotherapy you need and exactly where you need it.

Having external radiotherapy for prostate cancer

You have external radiotherapy for prostate cancer in a hospital radiotherapy department. You usually have it as an outpatient each weekday over 4 to 8 weeks.

Side effects of prostate cancer radiotherapy

Radiotherapy to the prostate can cause some side effects, such as loose or watery poo (diarrhoea) and passing urine more often.  

Long term side effects of prostate cancer radiotherapy

You might have long term side effects after having external radiotherapy for prostate cancer. This includes problems getting an erection and bowel and bladder problems. 

Last reviewed: 
15 Jun 2022
Next review due: 
15 Jun 2025