Effects of radiotherapy on men

Radiotherapy treats cancer by using high-energy rays that destroy cancer cells. It can be given as external radiotherapy using x-rays, or as internal radiotherapy using a radioactive material. It is usually safe to have sex while having external radiotherapy.

Radiotherapy can affect your sexual function directly or indirectly. Direct effects can be caused by treatment that affects the sex organs or sex hormones.

Radiotherapy to the pelvis may be given to treat cancers of the prostate, rectum, anus, bladder, penis or testicles. Pelvic radiotherapy can cause the skin in the genital area to become sore and red. You may also have some diarrhoea and feel sick. Sometimes men need to pass urine or bowel motions more frequently and urgently. Pelvic radiotherapy can also reduce your ability to have an erection.

Side effects are often temporary but sometimes they can be permanent. Your doctor and nurse will be able to tell you more about how you may be affected and what can help you manage side effects.

Effects of radiotherapy on your sex life

Radiotherapy treats cancer by using high-energy rays that destroy the cancer cells. It can either be given as external radiotherapy from outside the body using x-rays, or from within the body as internal radiotherapy (brachytherapy).

Usually, there will be no medical reason to stop having sex during external radiotherapy. But, if you have unpleasant side effects from the treatment, you may lose interest in sex until you recover. If you have radiotherapy to the area between the hips (pelvis), or if you have internal radiotherapy, your doctor or specialist nurse can tell you if this will affect your sex life during treatment.

We have more information about radiotherapy and its side effects.


Treatment that may directly affect sexual function

Radiotherapy may directly affect sexual function. It is important to remember that not everyone will have the side effects we mention in this section. Your cancer doctor or nurse can answer any questions you may have about your treatment, and how it might affect you.

Treatments for cancers in the pelvic area (area between the hips) are the most likely to affect sexual function. These can include treatment for cancers of the:


Pelvic radiotherapy

This type of radiotherapy may be used to treat cancers of the prostate, anus, rectum and bladder. Radiotherapy to the pelvis may also be given as part of total body irradiation for some people having a stem cell transplant. Because it is given in the area close to the sex organs, this type of radiotherapy may directly affect your sex life.

During treatment with pelvic radiotherapy, you might not feel interested in having sex due to side effects in the area. Skin in the treatment area often becomes red, and may be sore or itchy. The skin in the groin and anal areas are very sensitive, so this can make sex difficult.

Pelvic radiotherapy can also cause side effects such as diarrhoea and feeling sick (nausea). Your bladder or rectum may be sore and may bleed. You may need to pass urine or bowel motions more often and more urgently than usual. Most of these side effects are temporary, but rarely some can be permanent. There are different ways you can cope with urinary and bowel changes.

We have more information about the possible side effects of pelvic radiotherapy.


Erectile dysfunction (ED)

Pelvic radiotherapy can reduce your ability to have an erection. You may get an erection but then lose it, or you may be unable to have an erection at all. This can happen because blood vessels in the area narrow and don’t let enough blood through to fill the penis.

After pelvic radiotherapy, ED usually starts slowly a few months after treatment. It can continue to get worse for up to three years after treatment.

Your doctor or specialist nurse may suggest a recovery package, called penile rehabilitation to try to reduce ED.


Changes in ejaculation

During radiotherapy, and for a few weeks afterwards, some men have a sharp pain when they ejaculate. This is because radiotherapy can irritate the tube that carries semen out of the body (the urethra).

After pelvic radiotherapy, you will make less semen. This happens gradually after external radiotherapy. But after internal radiotherapy (brachytherapy) for prostate cancer, it happens soon after treatment.

When you ejaculate, you may notice only a small amount of fluid comes out. Some men don’t make any semen. You will still orgasm (climax), but it may feel different from before. If you cannot ejaculate, it is not possible to father a child through sex. Your doctor can talk with you about fertility treatments if this is important to you.


Changes to the anus and rectum

Pelvic radiotherapy can affect the anus and rectum. This can affect your sex life if you take part in anal sex or anal play as the receiving partner.

During radiotherapy, and for a few weeks afterwards, rectal pain may make anal penetration very uncomfortable or not possible. Side effects during treatment, such as diarrhoea or incontinence, may cause embarrassment and discomfort.

Radiotherapy treatment can cause long-term changes to the rectum. How much the rectum is affected depends on where the cancer was in the pelvis, and the type of radiotherapy you had. In some people, the rectum loses its stretchiness and can be injured more easily. Sometimes anal sex may no longer be possible. Your cancer doctor can tell you more about this.

After pelvic radiotherapy, if you want to have receptive anal sex, you may need to start gradually before building up to full penetration. You may need to be more cautious than before. The anal and rectal tissues are more fragile and less able to heal after pelvic radiotherapy. It is important to prevent injury to your rectum, as it can be a very serious problem. You can speak to your doctor about whether it is safe for you to have receptive anal sex.


Hormonal changes

Occasionally, men who have had pelvic radiotherapy make less testosterone. You may be able to have testosterone replacement therapy. But this is not usually suitable for men who have had treatment for prostate cancer.

Back to Effects of treatment on a man's sex life

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