Having external beam radiotherapy

You have external beam radiotherapy as an outpatient in the radiotherapy department. Radiotherapy is given using a machine that is like a big x-ray machine. This is called a linear accelerator (often called a LINAC).

You usually have it as a series of short, daily treatments. The treatments are given from Monday to Friday, with a rest at the weekend. Your course of treatment may last for 4 to 8 weeks. Radiotherapy is not painful, but you will need to lie still while you have it.

Some men have radiotherapy over 4 weeks instead of over 7 weeks. The total dose of radiation is the same for both. But when it is given over 4 weeks, the dose for each treatment session is higher. Doctors call this hypofractionation. Both are effective treatments. Your cancer doctor will recommend the best timing and way for you to have your radiotherapy.

The radiotherapy does not make you radioactive. It is safe for you to be with other people during external radiotherapy, including children.

Types of external beam radiotherapy

There are different types of external beam radiotherapy. They aim to treat the cancer while protecting healthy tissue. This reduces side effects.

You usually have either conformal radiotherapy or intensity-modulated radiotherapy (IMRT). They are both effective treatments for prostate cancer:

  • Conformal radiotherapy – Uses specially shaped radiation beams, so they match the shape of the cancer. This reduces damage to surrounding healthy tissue.
  • Intensity-modulated radiotherapy (IMRT) – Shapes the radiation beams and allows different doses of radiotherapy to be given to different areas. Lower doses are given to healthy tissue, which reduces the risk of damage.

Other types of radiotherapy are used less commonly:

  • Image-guided radiotherapy (IGRT) – This is usually done alongside IMRT. Images are taken before or during radiotherapy that show the size, shape and location of the tumour. These are used to make changes to the treatment area.
  • Stereotactic ablative radiotherapy (SABR) – This allows large doses of radiotherapy to be given to small areas very precisely, so you need fewer treatments. Different machines can be used to give SABR. It is only available in a research trial for prostate cancer.

Planning external beam radiotherapy

Your cancer doctor (oncologist) plans your radiotherapy carefully to make sure it is as effective as possible. On your first visit, you will have a planning CT scan. The scan helps them work out the exact dose and area of your treatment.

During the scan, you need to lie still and in the same position you will be in for your radiotherapy.

The person who gives you your treatment (radiographer) will make some permanent marks (tattoos) the size of a pinpoint on your skin. These are used to make sure you are in the correct position for every treatment session. The marks also show where the beams will be directed. This is only done with your permission. It may be a bit uncomfortable. If you are worried about this, talk to the radiographer.

Some men have tiny gold grains put into their prostate gland using an ultrasound scan. They act as markers that show the position of the prostate to help your cancer doctor plan each session of treatment. Having these markers can help reduce side effects and any possible damage to organs close to the prostate.

Advantages and disadvantages of external beam radiotherapy for early prostate cancer

You may want to think about the advantages and disadvantages of external beam radiotherapy when deciding about treatment.

Radiotherapy and radical prostatectomy are both treatments that may cure early prostate cancer. They are equally effective in treating the cancer.

To choose the treatment that is best for you, it can help to look at the different advantages and disadvantages of each one. You can then make your decision in partnership with your doctor.

Advantages

  • You do not need an operation or a general anaesthetic, which may have risks.
  • You can carry on doing most of the daily things you usually do.
  • Urinary problems may happen less often than after surgery.

Disadvantages

  • You have to go to hospital for 4 to 8 weeks, Monday to Friday, as an outpatient.
  • It can cause the side effects listed here. And some men may get bowel late effects.
  • It may be some time before the doctors know if treatment has been successful.
  • If the cancer comes back after radiotherapy, it is more difficult to have surgery to remove the prostate.

Advantages and disadvantages of external beam radiotherapy for locally advanced prostate cancer

You may want to think about the advantages and disadvantages of external beam radiotherapy when deciding about treatment. Your doctor may ask you to choose between two treatments.

Make sure you understand what each treatment involves and its advantages and disadvantages. You should also think about the immediate and long-term side effects.

Advantages

  • For some men, it may cure the cancer, and for others it may control it for many years.
  • If you are also having hormonal therapy, it can make this treatment more effective.
  • You have it as an outpatient.
  • You can carry on doing most of the daily things you usually do.

Disadvantages

  • You have to go to hospital for 4 to 8 weeks, Monday to Friday, as an outpatient.
  • It can cause the side effects listed here. And some men may get bowel late effects.
  • It may be some time before the doctors know if treatment has been successful.
  • If the cancer comes back after radiotherapy, it is more difficult to have surgery to remove the prostate.

Side effects of external beam radiotherapy

Side effects usually build up slowly after you start treatment. They may continue to get worse for a couple of weeks after treatment. But after this, most side effects improve gradually over the next few weeks.

Your doctor, nurse, or radiographer will talk to you about this. They will explain what to expect and give you advice on what you can do to manage side effects. Always tell them about your side effects. There are usually things they can do to help.

Side effects include:

  • Tiredness – this may last for up to a couple of months after treatment is over.
  • Skin changes – the skin in the treated area may become red or darken, or become flaky and itchy.
  • Bladder effects – you may feel you need to pass urine more often or have pain passing urine.
  • Bowel effects – you may get diarrhoea and sometimes pain in the back passage.

We have more detailed information about the side effects of external beam radiotherapy and about pelvic radiotherapy.

Possible late effects of external beam radiotherapy

Some men may have side effects that do not improve, or side effects that happen months to years after radiotherapy finishes. These are called long-term or late effects. Your doctor or nurse will explain these to you. There are different ways late effects of pelvic radiotherapy can be managed.

Possible late effects include the following:

Erection problems

Radiotherapy for prostate cancer can cause problems getting or keeping an erection. This is called erectile dysfunction (ED). Your age and if you are having hormonal therapy can also affect how likely you are to get ED. Most men with locally advanced prostate cancer will have hormonal therapy.

ED may not happen straight after treatment. It can develop slowly over 2 to 5 years. Ask your cancer doctor about your risk of ED. If you develop ED, there are different treatments that can help.

After radiotherapy and brachytherapy, some men ejaculate little or no semen.

Infertility

Radiotherapy to the prostate may cause permanent infertility. Some men may find this difficult to cope with. If you are worried, talk to your cancer doctor. You may be able to store sperm before treatment starts.

Bowel and bladder problems

Some men may have bowel or bladder changes because of radiotherapy. For example, blood vessels in your bowel and bladder can become more fragile. This may cause blood in your urine or from the back passage (bottom). If you notice any bleeding, always tell your doctor so they can check it out.

Let them know about any bowel or bladder symptoms you have. They can give you advice and may do some tests. You may also find it helpful to contact the Bladder and Bowel Community for support.

We have more detailed information about bladder and bowel changes after pelvic radiotherapy.

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 cancerinformationteam@macmillan.org.uk

    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: pathways.nice.org.uk/pathways/prostate-cancer (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.