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Radiotherapy to the pelvis

Radiotherapy uses radiation to kill cancer cells. It is used to treat 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 or urinary problems could have an impact of being close with another person.

Radiotherapy can be either external or internal. External radiotherapy targets radiation at the cancer from a radiotherapy machine outside of the body. Internal radiotherapy (brachytherapy) 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 internal radiotherapy for prostate cancer (brachytherapy). 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.

You may find radiotherapy to the pelvic area causes painful ejaculation, problems with erections and lowered interest in sex. 

Painful ejaculation

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

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

Radiotherapy to the pelvis might be used for prostate cancer, bladder cancer or lower bowel cancer. Erection problems are common after pelvic radiotherapy.

If you are 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. They are due to the radiotherapy causing scar tissue, which 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. Radiotherapy to the area close to 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. But it may take a bit of time, so don’t worry too much if you don’t feel like having sex for a while.

Last reviewed: 
06 Aug 2018
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