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Side Effects

External beam radiation therapy is noninvasive, so it is rare for side effects to show up immediately. With brachytherapy, there may be some swelling, soreness and frequent urination just after the procedure. However, these side effects are from the brachytherapy procedure rather than the radiation itself.

Over a period of weeks, radiation therapy may have other side effects develop:

  • Urinary frequency, urgency or a weaker stream are reasonably common side effects. Sometimes there is mild discomfort. The symptoms tend to be more noticeable with brachytherapy. You doctor can prescribe medication to help relieve these symptoms.
  • Changes in bowel habits are also common. There is usually some urgency or loose bowel movements. In some cases, you may have some diarrhea, increased gas or some mucus. Less commonly, some men have a flare of hemorrhoids. These side effects are temporary, with long-term symptoms less likely.
  • Mild tiredness may develop, starting in the middle of treatment. However, tiredness from radiation should improve within a few weeks after radiation treatment ends.
  • Mild skin irritation may occur with external beam radiation. Clean the area regularly with mild soap and warm water.
  • Impotence is a common side effect of any treatment for prostate cancer. The risk depends partly upon the ability to have an erection before treatment. Many men treated with radiation can maintain erectile function. Don’t be shy about talking to your doctor about your sex life. He or she may be able to suggest remedies or prescribe medication.
  • Infertility can often occur after radiation. If you wish to consider having children after radiation treatment, ask your doctor about sperm banking before treatment.
Very rare long-term potential side effects include hip injury, edema (swelling) or a second tumor from the radiation treatment.

Some side effects can be controlled with medications and changes to your diet. Ask your doctor or nurse whether you should make any changes in your diet. Tell them if you experience any discomfort so they can help you feel better.