Radiation therapy is an option for men with any stage of prostate cancer. Men with early stage prostate cancer may choose radiation therapy instead of surgery. It also may be used after surgery to destroy any cancer cells that remain in the area. In later stages of prostate cancer, radiation treatment may be used to help relieve pain.

Radiation therapy (also called radiotherapy) uses high-energy rays to kill cancer cells.This type of treatment uses high doses of radiation energy to treat cancer. Radiation therapy is an option when cancer is in your prostate but has not spread to other organs. It is also used when you cannot have surgery because of your age, health, or personal choice. There are two types of radiation therapy:

• External beam radiation. A machine aims radiation at your cancer cells. It rotates around your body, sending radiation from many directions. After the doctor maps out the exact part of your body that needs radiation, treatment usually happens once a day, 5 days a week, for 6 to 8 weeks. Each treatment session usually lasts about 15 minutes. The latest types of radiation are called 3-D Conformal Radiation Therapy and Intensity-Modulated Radiation Therapy (IMRT). These types of radiation are more precise in destroying cancer while leaving nearby healthy cells unharmed. They are designed to lower the exposure of the rectum and bladder to radiation to help lessen side effects.
• Brachytherapy. This is a type of internal radiation therapy. It is also called seed implants. Radiation is delivered inside your body by implanting tiny seeds in your prostate. Usually 40 to 130 seeds are inserted into the prostate, depending on the size of your prostate. Each seed has a small amount of radioactive material that emits radiation within an inch of its surroundings. Low-dose seeds are left in the prostate permanently, although their radiation lasts for only 3 to 6 months. This procedure is usually done on an outpatient basis, without a hospital stay.

Side effects depend mainly on the dose and type of radiation. You're likely to be very tired during radiation therapy, especially in the later weeks of treatment. Resting is important, but doctors usually advise patients to try to stay active, unless it leads to pain or other problems.

If you have external radiation, you may have diarrhea or frequent and uncomfortable urination. Some men have lasting bowel or urinary problems. Your skin in the treated area may become red, dry, and tender. You may lose hair in the treated area. The hair may not grow back.

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

There is an increased risk of bladder cancer and/or rectal cancer in men treated with radiation therapy.

Impotence and urinary problems may occur in men treated with radiation therapy. You can talk with your doctor about ways to help cope with these side effects.