Radiation therapy (also called radiotherapy) uses high-energy rays to kill cancer cells. It affects cells only in the treated area.
For early stage prostate cancer, radiation treatment may be used 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.
Doctors use two types of radiation therapy to treat prostate cancer. Some men receive both types:
External radiation: The radiation comes from a large machine outside the body. Men go to a hospital or clinic for treatment. Treatments are usually 5 days a week for several weeks. Many men receive 3-dimensional conformal radiation therapy. This type of treatment more closely targets the cancer. It spares healthy tissue.
Internal radiation (implant radiation or brachytherapy): The radiation comes from radioactive material usually contained in small seeds. The seeds are put into the tissue. They give off radiation for months. The seeds are harmless and do not need to be removed.
Side effects depend mainly on the dose and type of radiation. You are 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 as active as they can.
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.
Internal radiation treatment may cause incontinence. This side effect usually goes away. Lasting side effects from internal radiation are not common.
Both internal and external radiation can cause impotence. Internal radiation is less likely to have this effect.
You may want to ask your doctor these questions before choosing radiation therapy: