Your body undergoes many changes when you have radiation treatment for cancer.

You may have the following side effects about 2 to 3 weeks after your first radiation treatment:

• Skin problems. The skin over the treated area may turn red, start to peel, or itch. This is rare.
• Bladder discomfort. You may have to urinate often. It may burn when you urinate. The urge to urinate may be present for a long time. Rarely, you may have loss of bladder control. You may see some blood in your urine. You should call your health care provider if that happens. In most cases, these symptoms go away over time, but some people may have flare-ups for years afterwards.
• Diarrhea and cramping in your belly, or a sudden need to empty your bowels. These symptoms can last for the duration of therapy. They often go away over time, but some people may have diarrhea flare-ups for years afterwards.

Other effects that develop later may include:

• Problems keeping or getting an erection may occur after prostate radiation therapy. You may not notice this problem until months or even a year or more after therapy is finished.
• Urinary incontinence. You may not develop or notice this problem for several months or years after radiation is complete.
• Urethral stricture. Narrowing or scarring of the tube that allows the urine to pass out of the bladder may occur.

Your provider will draw colored markings on your skin when you have radiation treatment. These markings show where to aim the radiation and must stay in place until your treatments are finished. If the marks come off, tell your provider. Do not try to redraw them yourself.

To take care of the treatment area:

• Wash gently with lukewarm water only. Do not scrub. Pat your skin dry.
• Ask your provider what soaps, lotions, or ointments are OK to use.
• Do not scratch or rub your skin.

Drink plenty of liquids. Try to get 8 to 10 glasses of fluids a day. Avoid caffeine, alcohol, and citrus juices such as orange or grapefruit juice if they make the bowel or bladder symptoms worse.

You can take over-the-counter diarrhea medicine to treat loose stools.

Your provider may place you on a low-residue diet that limits the amount of fiber you eat. You need to eat enough protein and calories to keep your weight up.

Some people who get prostate radiation treatment may begin to feel tired during the time they are having treatments. If you feel tired:

• Do not try to do too much in a day. You may not be able to do everything you are used to doing.
• Try to get more sleep at night. Rest during the day when you can.
• Take a few weeks off work or cut back on how much you work.

It is normal to have less interest in sex during and right after radiation treatments. Your interest in sex is likely to come back after your treatment is over and your life starts to return to normal.

You should be able to enjoy sex safely after radiation treatment is over.

Problems with having an erection are often not seen right away. They may show up after a year or more.

Your provider may check your blood counts regularly, especially if the radiation treatment area on your body is large. At first, you will have PSA blood tests that will be checked every 3 to 6 months to check the success of the radiation treatment.

Radiation - pelvis - discharge

National Cancer Institute website. Prostate Cancer Treatment (PDQ) - patient version. www.cancer.gov/types/prostate/patient/prostate-treatment-pdq. Updated February 16, 2023. Accessed July 24, 2023.

Phillips R, Hazell S, Song DY. Radiation therapy for prostate cancer. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 157.

Zeman EM, Schreiber EC, Tepper JE. Basics of radiation therapy. In: Niederhuber JE, Armitage JO, Kastan MB, Doroshow JH, Tepper JE, eds. Abeloff's Clinical Oncology. 6th ed. Philadelphia, PA: Elsevier; 2020:chap 27.

Updated by: Kelly L. Stratton, MD, FACS, Associate Professor, Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.