For Radiation Oncologists

In a prospective, randomized, multi-center, patient-blinded, clinical trial, patients that received the breakthrough SpaceOAR® hydrogel technology prior to their prostate cancer radiotherapy demonstrated significant rectal (bowel), urinary, and sexual benefit through 3 years of follow up. Read the full study here.

How does SpaceOAR hydrogel work?

*Control patients experienced a clinically significant (1X MID) decline in bowel, urinary and sexual QOL 8 times more often than SpaceOAR hydrogel patients.2,3

Reliable Space Creation1


  • 99% procedural success rate
  • Zero device adverse events
  • 1.3 cm space creation
  • Hydrogel lasts for 3 months and is then fully absorbed and cleared in the patient’s urine

Reduced Dose to Rectum and Penile Bulb


  • 73.5% relative reduction in rectal V70 dose1
  • 48.8% relative reduction in median penile bulb dose2
  • 97.3% of subjects had at least a 25% relative reduction in V701

Resulting in Lower Late Rectal Toxicity vs Control2

Rectal Toxicity

  • 75% relative reduction in late grade 1+ rectal toxicity
  • 100% relative reduction in late grade 2+ rectal toxicity
  • Zero late grade 2+ rectal toxicity
  • 73% relative reduction in cumulative grade 1+ urinary incontinence

And Better Quality of Life (QOL) vs Control at 3 Years Follow-up


  • Bowel: 66% fewer SpaceOAR hydrogel patients experienced clinically significant declines in detectable bowel quality of life (1X the Minimal Important Difference)2
  • Urinary: 65% fewer SpaceOAR hydrogel patients experienced clinically significant declines (2X the Minimal Important Difference) in detectable urinary quality of life2
  • Sexual: SpaceOAR hydrogel patients who had erections sufficient for intercourse at baseline were 78% more likely to retain sexual function at 3 years3

Overall well-being: Control patients were 8 times more likely than SpaceOAR hydrogel patients to experience a clinically significant decline in all three quality of life domains combined (bowel, urinary and sexual)2,3

1) N Mariados et al. Hydrogel Spacer Prospective Multicenter Randomized Controlled Pivotal Trial: Dosimetric and Clinical Effects of Perirectal Spacer Application in Men Undergoing Prostate IMRT. Int J Radiat Oncol Biol Phys. 2015 Aug 1;92(5):971-7.

2) Hamstra D, et al. Continued Benefit to Rectal Separation for Prostate RT: Final Results of a Phase III Trial. Int J Radiat Oncol Biol Phys; Dec. 2016 DOI

3) Hamstra D, et al. Evaluation of sexual function on a randomized trial of a prostate rectal spacer. J Clin Oncol 35, 2017 (suppl 6S; abstract 69)