What is a rectal spacer?

When you have radiation therapy for prostate cancer, a rectal spacer may be used to limit how much radiation goes to your rectum. The rectum is the last part of your large intestine. There are a few types of rectal spacers. Some are made from a special gel or liquid that’s injected in between your rectum and prostate. Others use a small balloon filled with liquid. The spacer moves your rectum farther away from your prostate. This may help shield or limit how much radiation your rectum gets. But it also allows the prostate to get a full dose to treat the cancer.

Why is it used?

Radiation therapy is used to kill cancer cells. But it can also harm healthy cells in the area. This includes the rectum, which is behind the prostate. Some doctors may recommend using a rectal spacer to help protect the rectum from getting radiation aimed at the prostate. This may lower your chance of having side effects and other rectal problems caused by the radiation.

How is it placed?

You may have a rectal spacer put in before you start radiation treatments. This is usually done as an outpatient procedure. This means you won’t need to stay in the hospital.

You'll get anesthesia before the procedure. It may make you sleep. Or it may just numb the area.

Depending on the type of spacer used, the doctor may inject a special water-based gel or liquid into the area between your prostate and rectum. Or the doctor may put in a balloon that's filled with liquid. This creates a space by pushing the front wall of the rectum away from the prostate. The doctor uses ultrasound to help see the prostate and rectum while placing the spacer.

The procedure may take about 30 minutes to an hour. It's often done at the same time as a procedure that places tiny metal markers on the prostate to help doctors aim the radiation.

A rectal spacer will stay in place while you have your radiation treatments. It gets absorbed by your body in about 3 to 6 months. So you don’t need to have a procedure to remove the spacer.

What are the risks of using a rectal spacer?

Like any surgery or procedure, there are some risks to using a rectal spacer. These may include infection, bleeding, and other problems. Some of these problems can be serious. Talk to your doctor about the possible benefits and risks.