Prostate cancer treatment: radiation therapy (radiotherapy)

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Radiation therapy (radiotherapy) for prostate cancer targets high-energy rays or particles at the prostate to destroy cancer cells. It’s commonly used alongside hormone therapy.

There are 2 main types of radiation therapy: external beam radiation therapy (EBRT) and brachytherapy (or internal radiation). Both types use radiation to kill prostate cancer cells, but they work in different ways.

External beam radiation therapy directs high energy x-rays at the entire prostate to treat the cancer. If the cancer has spread to the lymph nodes just outside the prostate, this area around the prostate is sometimes also targeted.

Brachytherapy is a form of internal radiation therapy, also called seed implantation or interstitial radiation therapy. There are 2 types: low dose rate (LDR) and high dose rate (HDR) brachytherapy. Either type can be used alone or combined with external radiation.

In this article, we’ll talk more about external beam radiation therapy. You can learn more about brachytherapy and its side effects here.

When is radiation therapy used for prostate cancer?

Radiation therapy is usually used to treat cancer that is only within the prostate (‘localized’) as well as cancer that has spread into the surrounding area (‘locally advanced’).

Sometimes it can be used in advanced (metastatic) prostate cancer—where the cancer has spread outside the prostate and surrounding areas.

    Some other reasons for using radiation therapy include:

  • After surgery to reduce the risk of cancer returning or if the cancer was not completely removed.

  • After surgery if there are signs that cancer has returned.

  • In combination with hormone therapy.

Your doctor or care team can help you decide if radiation therapy is right for you. They will also tell you if they recommend having it alongside hormone therapy.

How long does external beam radiation therapy last?

Radiation therapy is non-invasive—that is, the machine doesn’t touch you. The treatment is given to you as an outpatient, and you should be able to go home after each session. The radiation oncologist will make a plan with you to determine how many treatments you need and how often you’ll need them. Typically:

  • Each treatment session is scheduled for 15 to 20 minutes, with the beams usually on 5 or fewer minutes.

  • Treatment is given 5 days a week—usually Monday to Friday with weekends and holidays off to rest.

  • You will usually have up to 20 sessions, so the schedule is around 4 weeks, but it can go for up to 8 weeks. During treatment your team will regularly review your progress and how the treatment is working.

Stereotactic body radiation therapy

Stereotactic body radiation therapy (SBRT) is a newer type of external beam treatment. It is usually 2 to 5 treatments—and is given every other day or once a week. SBRT is available at a growing number of cancer centers, but not all. Speak to your doctor to find out more on SBRT, and whether it is available and suitable for you.

What are the common side effects of external beam radiation therapy?

Radiation therapy affects each man differently and comes with some side effects. Usually, the issues don’t last forever, and many men are able to keep up a good quality of life. Most side effects start midway through treatment. They can persist for around two weeks and then tend to get better over a 6-week period. If you’re having any trouble with these body changes, speak to your doctor or care team right away. They can guide you towards helpful solutions and relief.

  • Needing to urinate (pee) often (urinary frequency)

  • Suddenly feeling you have to urinate (urinary urgency)

  • Burning sensation when you urinate

  • Having a hard time urinating, or feeling like you need to push it out

  • Blood in your urine—this could appear several years after treatment

Learn more about managing urinary problems.

  • Diarrhea

  • Passing gas (or farting), more than usual

  • Needing to go to the bathroom more often

  • Leaking a clear, jelly-like mucus from your bottom

  • Bleeding from your butt or anus

  • A feeling that you haven’t fully emptied your bowels, and there’s more that needs to come out

Learn more about bowel issues.

You can feel exhausted or drained of energy as you go through treatment. Sometimes these feelings can happen after treatment is finished too. Learn more about fatigue and how to manage it.

  • Uncomfortable or dry orgasms

  • Painful ejaculation (may last for a short or long time)

  • Rusty colored semen (for a short time)

  • Erection problems (problems can appear after up to 2 years after treatment)

Although some men experience problems immediately after receiving radiation therapy, loss of erections becomes more of an issue over time. Learn more about sex after radiation therapy for prostate cancer.

Radiation therapy can greatly affect your fertility. If you’d like to father children in the future, speak to your doctor or care team about saving (banking) your sperm before you have treatment. The sooner you have this conversation, the better.

Recovering from external beam radiation therapy

After external beam radiation therapy, you’ll have regular check-ups with your doctor to monitor your progress. Speaking up about what you’re going through will become very important. Let your doctor or care team know what side effects you’re experiencing right away, so you don’t have to handle it alone. As you work through recovery, try to stay hopeful about the journey ahead.