The Goal of Radiation Therapy for Prostate Cancer

Radiation treatment is also called radiotherapy. Its goal is to use radiation to kill or shrink cancer cells.

There are two ways to get radiation:

• External radiation comes from a machine similar to an X-ray machine. This is sometimes called EBRT, which stands for external-beam radiation therapy.

• Internal radiation is when a radioactive material is placed inside you. It’s put directly into, or near, the tumor. With prostate cancer, this is called interstitial seed placement. It's also called brachytherapy. Brachy means near and refers to how close the radiation is to your tumor.

You may get only one of these types of radiation, or both of them.

If you have early-stage prostate cancer, radiation can often be as effective as surgery to cure your cancer. Stage I or II is considered an early stage.

If your cancer has spread to areas near your prostate, your radiation oncologist may choose to add hormone therapy to external radiation. You may start hormone treatment before getting radiation or at the same time it starts. Hormone therapy often continues after radiation ends.

If your cancer has spread beyond your prostate and the nearby areas and has reached other parts of the body, such as the bones, your doctor may use radiation to shrink the cancer and ease symptoms.

Making the decision to have radiation therapy

Your doctor may suggest radiation treatment if any of these statements is true for you:

• You have a slow-growing, localized prostate cancer without any evidence of cancer spread. In this case, you may have only external radiation, only internal radiation, or both.

• You have surgery for localized cancer, but there are signs the operation did not remove all of the cancer. For example, if the cancer is found to have grown into tissues near the prostate or if the PSA level remains detectable a few months after surgery, radiation therapy may be recommended. 

• You have a faster-growing (Gleason of 8 or higher), localized prostate cancer, or a cancer that has grown outside the prostate (but has not spread to lymph nodes or further). In this case, your doctor may recommend external radiation, usually along with hormonal therapy.

• You're having pain from prostate cancer that has spread to your bones. In this case, your doctor might recommend external radiation or other medical treatments to try to shrink the cancer and help relieve your symptoms.

• You've already had surgery or another treatment for localized prostate cancer and your cancer has come back. In this case, your doctor might recommend external radiation to try to destroy any remaining cancer cells.

For this treatment, you'll talk with a doctor who specializes in both cancer and radiation, called a radiation oncologist. This doctor will tell you what type of radiation you need, at what dose, and for how long. During your visit, ask what you can expect to feel during and after the treatment.