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Radiation effects on men

There is always the potential for some side effects to occur when radiation therapy is given to the pelvic area. Radiation can affect a man’s reproductive organs. Changes in reproductive organ function depend on:

  • the amount of tissue treated
  • the dose of radiation therapy given

Side effects may occur during or after radiation therapy. Side effects may go away once treatment is over, but some may continue after radiation treatment is finished.

Fertility problems

Fertility problems can occur with radiation to the pelvic area. Although the radiation team tries to shield a man’s reproductive organs from radiation unless they contain cancer, some radiation scatter (radiation energy that is given off outside the treatment area) is unavoidable. As a result, the testicles may be exposed to small amounts of radiation.

The testicles are very sensitive to the effects of radiation. Radiation can reduce the number of sperm produced or damage sperm and affect their ability to function. Temporary or permanent infertility (inability to father a child) can occur because of radiation to the testicles.

The radiation therapy team can tell you if and when it is safe to have sex while receiving radiation to the pelvic area. They will also let you know if you should take any special precautions during or after radiation treatment.

Men and their partners may have concerns about future childbearing. Before treatment starts, they should talk to their doctor about the effects radiation treatment may have on their ability to have children and fertility options.

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Erectile dysfunction

Radiation therapy to the pelvic area may cause erectile dysfunction (ED). ED means that a man can’t get or keep an erection. It happens because radiation lowers testosterone levels and can affect the arteries that carry blood to the penis, which is necessary for a firm erection.

The risk for ED is lower in men who have brachytherapy instead of external beam radiation therapy.

Men should talk to the radiation therapy team if they are concerned about ED or are interested in treatment options.

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Effects of radiation on a boy’s reproductive system

Boys who receive radiation to the pelvis may experience:

  • lack of testosterone production
    • If the testicles are affected by radiation, they may not produce male sex hormones.
    • A lack of male sex hormones prevents the development of secondary sex changes, such as growth of facial hair, development of heavy bones and muscles and lowering of the voice.
    • This is a rare side effect of radiation to the testicles.
  • low sperm count or temporary zero sperm count (azoospermia) with low doses of radiation to the testicles
  • infertility with higher doses of radiation
    • Infertility may sometimes occur with low doses of radiation because testicular tissue is very sensitive to radiation.

Every effort is made to shield the testicles from radiation unless they contain cancer, but sometimes radiation scatter (radiation energy given off outside the treatment area) occurs and the testicles receive small amounts of radiation that will affect their functioning.

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A type of radiation therapy that uses implants (needles, catheters, wires or seeds) to deliver radiation directly into or near a tumour.

Brachytherapy may be interstitial (placed directly in the tumour), intracavitary (placed in a body cavity, such as the uterus or vagina) or intraluminal (placed in a tube or passage in the body, such as the esophagus or bronchi).

Also called internal radiation therapy, implant therapy or seed therapy.


Brock Taraba Brock has been cancer free for over a decade, thanks to the support we received from the Canadian Cancer Society.

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Some cancers, such as thyroid and testicular, have survival rates of over 90%. Other cancers, such as pancreatic, brain and esophageal, continue to have very low survival rates.

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