FDA grants 510(k) clearance to SpaceOAR Flex Hydrogel for prostate radiotherapy

The FDA has granted 510(k) clearance to the SpaceOAR Flex Hydrogel as a rectal spacer in men undergoing radiation therapy for prostate cancer.¹

The device is intended to temporarily position the anterior rectal wall away from the prostate during prostate cancer radiotherapy, with the goal of reducing the radiation dose to the rectum. The clearance expands Boston Scientific’s SpaceOAR portfolio and follows earlier FDA clearances for SpaceOAR Hydrogel and SpaceOAR Vue Hydrogel.

SpaceOAR Flex is designed with a flexible hydrogel delivery system that allows the physician to pause delivery, evaluate placement, and adjust delivery in real time, according to press communication from Boston Scientific. The system also uses a single-syringe delivery approach and is designed to reduce setup steps compared with the SpaceOAR Hydrogel and SpaceOAR Vue systems.

“Rectal spacing has become an important tool for physicians seeking to limit radiation exposure to healthy tissue during prostate cancer treatment,” said Ronald Morton, MD, chief medical officer, Urology, Boston Scientific, via press communication from Boston Scientific. “SpaceOAR Flex Hydrogel builds on our experience in this category and provides physicians with another option based on their clinical and workflow needs.”

The company also noted that SpaceOAR Flex is designed to be visible on computed tomography (CT) scans, including kV cone-beam CT, similar to SpaceOAR Vue. According to the company, this visibility is intended to facilitate contouring of the prostate and rectum during treatment planning and to assist with patient positioning during image-guided radiotherapy.

The device is being assessed in the multicenter HYDROSPACE trial (NCT06451614). Preliminary results from the study will be presented at the 2026 American Society for Radiation Oncology Annual Meeting in Boston, Massachusetts.

The randomized controlled trial is assessing the effectiveness and safety of the SpaceIT Hydrogel System for perirectal spacing in patients who are undergoing external beam radiotherapy for the treatment of low to intermediate risk prostate cancer. Participants in the control arm received either the SpaceOAR System or SpaceOAR Vue Hydrogel.²

Boston Scientific said it expects to begin a limited US market release of SpaceOAR Flex later in 2026. SpaceOAR and SpaceOAR Vue will continue to be commercially available for rectal spacing.

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REFERENCES

1. 510(k) Premarket Notification. US Food & Drug Administration. Accessed September 25, 2026. https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm?ID=K262151

2. SpaceIT Hydrogel System for Perirectal Spacing (HYDROSPACE). ClinicalTrials.gov. Last updated September 14, 2026. Accessed September 25, 2026. https://clinicaltrials.gov/study/NCT06451614