Doctors sometimes recommend radiation therapy after a prostatectomy for cancer that has a high risk of returning. Radiation therapy is also used to treat cancer that has returned after surgery.

Prostate cancer that’s limited to the prostate is often treated with surgery. The main type of surgery used to treat prostate cancer is called radical prostatectomy. This procedure involves removing the entire prostate gland or surrounding tissues or lymph nodes.

If your cancer has a high risk of coming back after surgery, your doctor may recommend radiation therapy to kill any remaining cancer cells that might not be detected. Radiation therapy may also be an effective second therapy if your cancer returns.

In this article, we examine when doctors may recommend radiation therapy after prostatectomy.

Radiation therapy is used in two main ways after surgery:

  • Adjuvant therapy is used to destroy cancer cells that may not have been removed during surgery before there’s evidence of reoccurrence confirmed with a prostate specific antigen (PSA) test.
  • Salvage therapy is used to destroy cancer cells once there’s evidence that the cancer has come back confirmed with a PSA test.

Adjuvant radiation therapy

The primary goal of adjuvant radiation therapy after prostate surgery is to eradicate cancer cells that are not detectable and to prevent reoccurrence. It’s primarily offered to people whose cancer is deemed at high risk of reoccurrence after surgery.

It’s not widely used in people whose cancer typically has a low risk of returning to help prevent overtreating the cancer and causing additional side effects.

Your doctor may recommend adjuvant radiation therapy if you have:

  • Localized prostate cancer: This is cancer that has not spread beyond your prostate.
  • Locally advanced cancer: This is cancer that has spread to nearby tissues.

Radiation therapy is usually administered within 4–6 months of surgery.

Salvage radiation therapy

Salvage therapy is administered after biochemical failure. Biochemical failure means that your PSA levels are abnormal, suggesting that your cancer has returned.

Clinicians and researchers still debate whether it’s better to administer radiation therapy as an adjuvant therapy or salvage therapy.

Radiation therapy can cause bowel, urinary tract, and sexual health problems. Possible side effects of radiation therapy include:

Learn more about radiation therapy side effects.

Doctors usually administer radiation therapy in 1–4 treatments over about 2 days.

If radiation therapy is not effective, doctors rarely perform another round since additional radiation can increase your risk of serious side effects.

Doctors may sometimes administer internal radiation therapy if you previously received external beam radiation therapy.

Learn more about the types of radiation therapy used to treat prostate cancer.

Radiation therapy after surgery can be very effective in treating cancer confined to the prostate or surrounding area.

In a 2021 study, researchers found no biochemical evidence of prostate cancer for 5 years in 88% of people treated at one center between 1997 and 2013. They found no evidence in 72% of people after 10 years.

In a 2020 review of studies, researchers found that the 5-year recurrence-free survival rate was about 60% when internal radiation therapy was used as a salvage therapy. Research also suggests that salvage radiation therapy is linked to better outcomes than observation alone.

Researchers continue examining the effectiveness of a newer type of radiation therapy called proton therapy. Proton therapy may potentially reduce complication rates while being equally as effective. It’s currently only available at a limited number of treatment centers, and it’s expensive.

The effectiveness of adjuvant radiation therapy is well established, but researchers are unsure if performing adjuvant or salvage radiation therapy is linked to better outcomes.

In a 2020 review of studies published in the Lancet, researchers found no evidence that performing radiation therapy before symptoms occurred was linked to better outcomes than salvage therapy.

The 5-year event free survival rate was only 1% higher among people who received radiation therapy before symptoms developed compared to people who received radiation afterward at 89% versus 88%.

The 5-year event free survival rate is a measure of how many people do not have cancer progression for 5 years.

Radiation therapy is sometimes given before surgery to help shrink the cancer and make it easier to treat. Radiation therapy administered in this way is called neoadjuvant therapy.

Neoadjuvant radiation therapy may be administered alone or with:

The use of neoadjuvant radiation therapy is still under investigation. Current research suggests that it may not be linked to better cancer outcomes than surgery alone.

Radiation therapy is sometimes administered after surgery to treat prostate cancer if it has a high risk of reoccurring. Radiation therapy can destroy remaining cancer cells that may not be detectable.

Doctors also use radiation therapy to treat prostate cancer that has returned after surgery. When it’s used in this way, it’s called salvage therapy.

Your care team can help you determine if radiation therapy is treatment option.