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Radiotherapy| treats cancer by using high-energy rays (radiation) that destroy the cancer cells, while doing as little harm as possible to normal cells.
Radiotherapy can either be given as external radiotherapy| from outside the body using x-rays, or from within the body as internal radiotherapy|.
Radiotherapy can cause side effects, such as fatigue| (tiredness that doesn’t go away with rest) that can last for several weeks or months. In this situation sex may be one of the last things on your mind, or you just may be too tired to actually have sex.
Radiotherapy can also cause a skin reaction. The skin can be very sensitive in the groin, perineum and anal areas, and, in women, the vulva. If a skin reaction does occur, it can make sex difficult and painful.
Radiotherapy to the pelvic area can also cause other side effects, such as diarrhoea| and nausea| (feeling sick). Some people also get inflammation of the bladder (cystitis) or rectum, which can cause pain and bleeding. Some women may also have vaginal bleeding. These side effects can either make sex difficult or affect your desire to have sex. Most of these side effects are temporary, but very rarely they can be permanent. There are ways to cope with some of these side effects|. We have more information about pelvic radiotherapy for men| and women|.
A possible long-term side effect of radiotherapy is damage to the tiny blood vessels close to the surface of the skin. This will cause red spidery marks on the skin and is called telangiectasia. These blood vessels can be delicate and are more likely to bleed. Telangiectasia may affect how you feel about the way you look, or make sexual contact difficult if the skin is fragile.
In women, radiotherapy can affect sexual function when it’s given to the pelvic area for cancers of the anus|, rectal|, bladder|, vagina|, vulva|, cervix| and womb| (endometrium). Women who receive radiotherapy as part of their treatment for leukaemia| (total body irradiation) or lymphoma| may also experience vaginal changes. After high-dose treatment with a stem cell or bone marrow transplant|, some women may develop graft versus host disease (GVHD|). This can cause the vaginal tissues to be affected, resulting in sexual difficulties.
Radiotherapy can cause damage to an unborn child. So if you haven’t yet had your menopause, you may be asked by the staff in the radiotherapy department to have a pregnancy test before you start your radiotherapy. You will need to use effective contraception throughout your radiotherapy treatment. You can discuss this with your doctor or specialist nurse.
If you’re already pregnant when your cancer is diagnosed and before your radiotherapy starts, it’s very important to discuss with your doctor the pros and cons of continuing with your pregnancy. It’s sometimes possible to delay starting radiotherapy until after the baby is born. This depends on the type of cancer| you have, the extent of the disease, and how advanced your pregnancy is. It’s important to be fully aware of all the risks and alternatives before making any decisions.
As well as talking to your doctor about your pregnancy, you can also talk to our cancer information specialists|.
Radiation to the pelvic area for cancer of the anus, rectum, bladder, endometrium, cervix, vagina or vulva, or for leukaemia or lymphoma, can affect the ovaries and reduce the production of female hormones. This is usually permanent but occasionally may be temporary for some women. The production of hormones gradually decreases over about three months. This will cause symptoms of the menopause, such as hot flushes, vaginal dryness and mood swings.
Until it’s confirmed that you have experienced the menopause (as a result of treatment), you may be advised to continue using contraception to avoid pregnancy.
Your doctor may be able to give you hormone replacement therapy (HRT), which can help reduce the impact of these changes. If you’ve had breast cancer| or a hormone-sensitive gynaecological cancer, you may be advised not to take HRT. Some complementary therapies| can help reduce menopausal symptoms. It may be helpful to discuss this with your doctor or specialist nurse.
A woman who has already had her menopause will have far fewer hormonal changes than a woman whose ovaries were still working before the radiotherapy treatment.
You may find our section about menopausal symptoms| helpful.
The vagina can be affected by radiotherapy to the pelvic area. It becomes sore and tender in the early stages and for a few weeks afterwards. Over time, this irritation may leave scarring. This makes the vagina narrower and less flexible, and also reduces the production of lubrication that’s normally associated with sexual arousal. This loss of lubrication can lead to pain caused by friction and irritation of the tissues during sex.
You may find it helpful to read our section about the possible late effects of pelvic radiotherapy for women|.
In men, radiotherapy may affect sexual function when it’s given to the pelvic area for cancers of the prostate|, anus|, rectum| and bladder|.
Radiotherapy to the pelvic area| can reduce a man’s ability to have an erection. Up to 70% of men (7 in 10) have problems getting or keeping an erection after radiotherapy for prostate cancer. In affected men, their erections aren’t as strong as they were before the treatment, and this gradually gets worse over a year or two.
ED occurs because the blood vessels that supply blood to the penis become scarred and are unable to let enough blood through to fill the penis. Some men may get an erection but then lose it. Other men are unable to have an erection at all. Treatment with drugs can help some men to get and maintain an erection after having radiotherapy.
Treatments that can help you overcome ED| are discussed in another section. It’s thought that using these treatments soon after radiotherapy may help to prevent erectile difficulties in some men.
Some men who have internal radiotherapy (brachytherapy|) for prostate cancer develop problems passing urine. They may need a tube into the bladder to drain urine (a catheter), or they may have leakage of urine (incontinence). Often these problems are temporary, but they may be permanent for some men.
In men who can still have and maintain erections, it’s very common to have dry ejaculations. When this happens, little or no semen is ejaculated at orgasm. This is not harmful but can worry you if you don’t expect it.
Some men feel a sharp pain as they ejaculate if they have recently had radiotherapy treatment. This is caused by radiation irritating the urethra. This problem usually disappears within a few weeks after the treatment has ended.
You might find our section about pelvic radiotherapy in men| useful.
For both men and women, radiotherapy to the pelvic area will cause infertility (the inability to have children). In women the ovaries will stop making eggs, and in men the production of sperm will stop. These changes can’t be reversed and infertility will be permanent. If you wanted to have children, this can be very difficult to cope with.
Radiotherapy given to other parts of the body may also affect the sexual organs, and could also cause infertility.
Please see our section on fertility and cancer| for more information.
It’s important that you discuss the risk of infertility fully with your doctor or specialist nurse before you start treatment. If you have a partner they will probably want to join you for this discussion. Then you can both be aware of all the facts and have a chance to talk over your feelings and the options for the future.
You might find it useful to read our section about radiotherapy|.
Content last reviewed: 1 October 2011
Next planned review: 2013
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If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.
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© Macmillan Cancer Support 2013
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