Minimizing Radiation Risks

Rectal Spacers: Added Protection During Prostate Radiation

If you're planning radiation therapy for prostate cancer, a rectal spacer is one of the most effective steps you can take to protect your quality of life afterward.

The prostate sits directly in front of the rectum — so close that radiation aimed at the prostate can also reach healthy rectal tissue, which can cause bowel side effects during and after treatment. A rectal spacer is a soft, gel-like material placed between the prostate and rectum before radiation begins. It gently creates a small space — just enough to move the rectum out of the high-dose radiation zone.

The spacer is placed in a brief outpatient procedure, does its job silently during your weeks of radiation, and is then naturally absorbed by the body. Clinical studies of hydrogel spacers have shown meaningful reductions in radiation dose to the rectum and in bowel side effects.

Experience precision

Experience Matters

Spacer placement is a precision procedure — the benefit depends on accurate, symmetric placement between the prostate and rectum.

Dr. Carlsen has been placing rectal spacers for Maui prostate cancer patients since 2019 and has performed hundreds of placements — experience built one patient at a time, here on Maui. His extensive training and experience in prostate cryotherapy and brachytherapy have contributed to every success story. He works closely with Maui and Oahu's radiation oncology teams to coordinate spacer placement (and fiducial marker placement, when needed) with your radiation planning schedule, so your treatment stays on track without flying off-island or paying exorbitant facility fees.

In rectal spacing, even complete coverage is critical. This provides the most protection against radiation exposure. Although we perform both Barrigel and SpaceOAR, we perform mostly Barrigel. First, Barrigel is gel made of Hyaluronic acid, a substance naturally present in the human body. Highly compatible and fully absorbable by the body, it is a natural substance used in many common medical procedures. Second, Barrigel can be viewed clearly on ultrasound. This added visibility during insertion provides us greater control and precision over the placement of the spacer. Barrigel remains soft during insertion, allowing us to sculpt the gel in place to create an optimal fit for your body.

What to Expect

The placement is a short outpatient procedure, typically done under local anesthesia and very light sedation with ultrasound guidance.
Most patients return to normal activity by the next day
Some men notice a temporary feeling of fullness; significant discomfort is uncommon.
The spacer remains in place through your radiation course and is absorbed by the body over the following months.

For Patients Starting the Radiation Process

If you've been diagnosed with prostate cancer and radiation is on the table, ask your radiation oncologist or call us directly about whether a spacer is right for you. Timing matters — the spacer is placed before radiation planning scans — so it's best to have this conversation early.

Physicians: to refer a patient for spacer or fiducial placement, call (808) 242-8765 or fax (808) 242-8769. We prioritize scheduling to keep radiation start dates on track.

call now