Radiotherapy to the pelvis for men

Radiotherapy uses radiation to kill cancer cells. It treats many different types of cancer.

Having radiotherapy could affect your sex life in several ways. For example, daily treatments for several weeks can make you very tired. You might not feel like having sex. Other side effects, such as diarrhoea and urinary problems, could have an impact of being close with another person.

Radiotherapy to the pelvis

Radiotherapy can be either external or internal. External radiotherapy uses a machine. This targets the cancer with radiation from outside of the body. 

Internal radiotherapy is also known as brachytherapy. It gives radiation from inside the body.

External radiotherapy

If you are having external radiotherapy treatment, it is fine to have intercourse if you both want to.

Internal radiotherapy

It is best to use condoms during intercourse for the first month after treatment if you had brachytherapy for prostate cancer. This applies to vaginal sex, anal sex or oral sex. This rarely happens, but there is a risk that a radiotherapy seed gets misplaced and is present in the semen.

Possible side effects of pelvic radiotherapy

You may find radiotherapy to the pelvic area causes:

  • painful ejaculation
  • problems with erections 
  • lowered interest in sex

Painful ejaculation

You may find that ejaculating is painful during your course of radiotherapy. This is because the urethra Open a glossary item gets inflamed by the radiation. This side effect should disappear a few weeks after you finish your treatment.

It might be best to avoid intercourse if it is painful. But you might be able to find other ways of enjoying sexual relationships.

Erection problems

You may have radiotherapy to the pelvis for:

  • prostate cancer
  • bladder cancer
  • lower bowel cancer

Erection problems are common after pelvic radiotherapy.

After having radiotherapy for bowel or bladder cancer, you might find that your erections are not as strong as before. Or you might be able to get an erection but then lose it. 

These side effects tend to come on gradually over several months following your treatment. The radiotherapy causes scar tissue. This damages the nerves and blood vessels that help you to get an erection. 

There are treatments that might help you get an erection.

Lowered interest in sex

You might feel less interested in sex following radiotherapy to the pelvis. Having radiotherapy near the testicles might lower your production of testosterone. Testosterone is the hormone that gives you your sexual desire. If you produce less testosterone, your interest in sex will be lower. But this does not happen to most men who have radiotherapy to the pelvis. 

You may feel that your desire for sex is lower, but it might be due to other reasons, including:

  • tiredness (fatigue)

  • anxiety about having cancer

  • loss of confidence and self esteem

  • side effects from other treatments such as cancer drugs

Usually these problems disappear once your treatment finishes. And your interest in sex will go back to normal. It may take a bit of time, so don’t worry too much if you don’t feel like having sex for a while.

Help and support

These changes and the emotions it can bring can be difficult to cope with. It might help to talk to a partner, relative or friend. Let your nurse, specialist or GP know how you are feeling. They can let you know what help and support is available in your treatment centre or in your area. 

Some people choose to talk things through with a counsellor or therapist. Or you could contact some of the organisations that offer support and information about relationships and sexuality.

Cancer Research UK nurses

For support and information, you can call the Cancer Research UK information nurses. They can give advice about who can help you and what kind of support is available. Freephone: 0808 800 4040 - Monday to Friday, 9am to 5pm.
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  • The Natural History of Erectile Dysfunction After Prostatic Radiotherapy: A Systematic Review and Meta-Analysis

    T Gaither and others 

    The Journal of Sexual Medicine, 2017. Volume 14, Number 9

  • Erectile function after stereotactic body radiotherapy for localized prostate cancer

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  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact patientinformation@cancer.org.uk with details of the particular issue you are interested in if you need additional references for this information.

Last reviewed: 
16 Oct 2024
Next review due: 
16 Oct 2027

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