Prostate Cancer Overview

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Treating Prostate Cancer TOPICS

Radiation therapy for prostate cancer

Radiation therapy is treatment with high-energy rays (such as x-rays) to kill cancer cells. It may be used to treat cancer in (and near) the prostate. It is also used to treat areas of cancer spread.

Radiation to treat prostate cancer may come from outside the body (external beam radiation) or from radioactive materials placed directly in the tumor (brachytherapy or internal radiation).

External beam radiation therapy (EBRT)

For this treatment, beams of radiation are focused on the prostate from a machine outside the body. This type of radiation can be used to try to cure earlier stage cancers, or to help relieve symptoms such as bone pain if the cancer has spread to a specific area of bone.

For earlier stage cancers, men usually have 5 treatments per week in an outpatient center over a period of about 7 to 9 weeks. Each treatment is painless and lasts only a few minutes, although the setup time — getting you into place for treatment — takes longer.

Newer EBRT techniques help doctors treat the prostate more precisely while reducing the radiation exposure to nearby healthy tissues. Some of these methods you may hear about are:

  • 3-dimensional conformal radiation therapy (3D-CRT)
  • Intensity modulated radiation therapy (IMRT)
  • Conformal proton beam radiation therapy
  • Stereotactic body radiation therapy (SBRT)

These methods might offer better chances of increasing the success rate and reducing side effects. If you are having one of the newer methods, your doctor can tell you more about it.

Possible side effects of EBRT

Some of the side effects from EBRT are the same as those from surgery, while others are different. Some common short-term side effects include:

  • Bowel problems: Diarrhea, sometimes with blood in the stool, rectal leakage, and an irritated large intestine are problems that usually go away over time, but in rare cases they don’t.
  • Bladder problems: You might need to urinate more often, feel burning while urinating, and maybe see blood in your urine. Bladder problems usually get better over time, but for some men they don’t go away, with the most common problem being the need to urinate often.
  • Trouble controlling urine (incontinence): This is less common with radiation than surgery, but the chance of incontinence goes up each year for several years after radiation treatment.
  • Erection problems: Some men may have erections that are not as firm as they once were, while others might not be able to get an erection strong enough to have sex. Erection problems usually don’t happen right after radiation therapy but develop slowly over a year or more. After a few years, the impotence rate after radiation is about the same as that after surgery. For more on coping with erection problems and other sexuality issues, see our document Sexuality for the Man With Cancer.
  • Feeling tired: Radiation treatment may cause severe tiredness. It may not go away until a few months after treatment stops.
  • Lymphedema: Fluid build-up in the legs or genitals is possible if the lymph nodes around the prostate are damaged by radiation. To learn more, see our document Understanding Lymphedema: For Cancers Other Than Breast Cancer.
  • Urethral stricture: The tube that carries urine from the bladder out of the body may, rarely, be scarred and narrowed by radiation. This can cause problems with urination, and might need further treatments to open it up again.

Brachytherapy (internal radiation)

For brachytherapy, radioactive materials are placed in the prostate. The risk of side effects to other areas is lower, because the radiation travels only a short distance. There are 2 main types of brachytherapy:

  • Permanent or low-dose brachytherapy uses small radioactive pellets or “seeds” that are put into the prostate. The seeds are not removed, but they lose their radioactivity over time. Each seed is about the size of a grain of rice.
  • Temporary or high-dose brachytherapy uses stronger radiation sources that are only left in place for a short time (less than 15 minutes). These radiation sources are put into soft tubes (called catheters) that have been placed in the prostate. Usually 3 treatments are given over a couple of days in the hospital. After the last treatment the catheters are removed.

Possible risks and side effects of brachytherapy

If you have pellets in place, they will give off small amounts of radiation for several weeks. Even though the radiation doesn’t travel far, you may be told to stay away from pregnant women and small children during this time. You may be asked to be careful in other ways, too, such as wearing a condom during sex.

For about a week after the pellets are placed, there may be some pain in the area and a red-brown color to the urine. There is also a small risk that some of the seeds might move to other parts of the body, but this is rare.

Like external radiation treatment, this approach can have side effects such as:

  • Bladder problems such as having to urinate often
  • Bowel problems such as rectal pain, burning, or diarrhea
  • Erection problems

Talk to your doctor if you have any problems. Often there are medicines or other methods to help.

More details about radiation therapy for prostate cancer can be found in our document Prostate Cancer.

Last Medical Review: 01/09/2015
Last Revised: 01/30/2015