Radiotherapy for prostate cancer

Radiotherapy is often given from outside the body by a machine. But it can also be given from inside the body (called brachytherapy).

What is radiotherapy?

Radiotherapy uses high energy rays to destroy cancer cells. At the same time, doctors try to make sure radiotherapy causes as little harm as possible to healthy tissue and organs close by. These include the bladder, back passage (rectum) and bowel.

Radiotherapy for prostate cancer can be given in different ways:

External beam radiotherapy is the most common way of giving radiotherapy for early prostate cancer and locally advanced prostate cancer. If you have brachytherapy, it may be given on its own or along with external radiotherapy.

We have information on radiotherapy for advanced prostate cancer.

Your cancer doctor may advise you to have hormonal therapy for up to 6 months before radiotherapy. Hormonal therapy can shrink the cancer, which helps make radiotherapy more effective. You may be given hormonal therapy before, during and after radiotherapy.

Side effects of radiotherapy for prostate cancer

Radiotherapy to the prostate causes different side effects. Most of these usually improve gradually after treatment has finished. Always tell your cancer team about your side effects. There is often something they can do to improve them. They can give you advice on how to manage them.

If you smoke, you should try to stop. Not smoking during and after radiotherapy can make treatment more effective and reduce the side effects.

Many hospitals provide help or advice on how to quit smoking. Ask your cancer doctor, radiographer or specialist nurse if your hospital provides this service. If they do not, your GP, a pharmacist or an organisation such as Smokefree will be able to help. We have more information to help you give up smoking.

We have more information on the side effects of external beam radiotherapy.

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About our information

  • References

    Below is a sample of the sources used in our prostate cancer information. If you would like more information about the sources we use, please contact us at

    European Association of Urologists. Guidelines on Prostate Cancer. 2016.

    European Society for Medical Oncology. Cancer of the prostate: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. 2015.

    National Institute for Health and Care Excellence (NICE). Prostate cancer overview. Available from: (accessed from March 2017 to November 2017).

    National Institute for Health and Care Excellence (NICE). Surveillance report 2016. Prostate cancer: diagnosis and management (2014). NICE guideline CG175. 2016.

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editors, Dr Jim Barber, Consultant Clinical Oncologist and Dr Lisa Pickering, Consultant Medical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.