Prostate Cancer: External-Beam Radiation Therapy (EBRT)

Prostate cancer may be treated with radiation therapy. It is also called radiotherapy. It works by sending radiation to the cancer sites. This can kill or shrink cancer cells. A radiation oncologist will create a treatment plan for you. This is a doctor who specializes in cancer and radiation therapy. Each person’s treatment plan is different. Your plan will include the type of radiation you will have. It will also include how often and for how long you will have the treatment.

There are 2 types radiation therapy for prostate cancer:

• External-beam radiation therapy (EBRT) from a machine similar to an X-ray machine

• Internal radiation or brachytherapy, which uses tiny radioactive seeds or tubes to send radiation to your prostate

You may be treated with one or both types of therapy.

Why might I need radiation therapy?

Your oncologist may advise radiation therapy if:

• You have a slow-growing cancer that has not spread outside your prostate gland. 

• You had surgery for prostate cancer, but there are signs the surgery did not remove all of the cancer. 

• You have a fast-growing cancer that is has not spread to lymph nodes.

• You're having pain from prostate cancer that has spread to your bones. EBRT may shrink the cancer and help relieve your pain.

• You've had surgery or other treatment and your cancer has come back. EBRT can help to destroy any cancer cells that are left.

Side effects of EBRT

Radiation therapy affects normal cells, as well as cancer cells. This can cause side effects. The side effects depend on the amount and type of radiation. They may occur during treatment. And they may occur in the weeks or months after EBRT. They may include:

• Redness, flaking, or fluid on the skin near the treatment area

• Diarrhea or intestinal cramping

• Blood in your stool

• Feeling tired

• Loss of hair, especially pubic hair

• Feeling the need to urinate often

• Burning feeling when you urinate

• Trouble having or keeping an erection

• Swelling of your penis, scrotum, or legs (rare)

Talk with your health care providers about any side effects you have. They may be able to help lessen them.

Types of EBRT

ERBT sends radiation from a machine outside the body. The most common types of EBRT used to treat prostate cancer include:

• Standard. Standard EBRT aims radiation at your prostate from one direction. This is much like that of getting an X-ray, only it lasts longer. This type of ERBT is not used as often anymore.

• Three-dimensional (3-D) conformal radiation therapy. This aims radiation from several directions. This can lessen the side effects on healthy tissue. 

• Intensity-modulated radiation therapy (IMRT). IMRT uses a computer to send radiation to specific areas. This also can lessen the side effects on healthy tissue.

Getting ready for EBRT

Before having EBRT, you may have a lymph node biopsy to see if your cancer has spread outside the prostate gland. One or more lymph nodes are removed to see if they contain cancer. Other tests may also be done.

Before your first treatment, you’ll have an appointment to plan for the treatment. This is called simulation. During this appointment:

• You’ll lie on a table while a radiation therapist uses a machine to find exactly where the radiation will be aimed. The therapist may mark your skin with tiny dots of permanent ink. These are used to aim the radiation at the exact same place each time.

• You may also have CT scans or other imaging to help locate the cancer.

• A plastic mold of your body may be made for some types of ERBT. The mold help you stay in the same position for each treatment.

What to expect for your treatment

You will receive ERBT at a hospital or clinic. You will likely not have to stay overnight. The length of time for your treatment depends on the type and dose of radiation. Your radiation oncologist or nurse can tell you what to expect during and after treatment.

What happens after EBRT?

After you finish your radiation therapy, your oncologist and other health care providers will closely watch your health. You will have regular lab tests and scans. Make sure you tell your health care providers about any symptoms you have. Make sure to go to all of your follow-up appointments.