Health Technology Brief

supporting sound, evidence-based decision making

Absorbable Perirectal Spacer (SpaceOAR System; Augmenix Inc.) During Radiation Therapy for Prostate Cancer

April 10, 2018

Health Problem: The National Cancer Institute estimates 161,360 new cases of prostate cancer (PCa) in 2017 and 26,730 deaths.

Technology Description: The SpaceOAR absorbable perirectal spacer (APS) is a polyethylene glycol hydrogel that is injected under anesthesia with transrectal ultrasound guidance into a space between the prostate and rectum. The APS is injected via dual syringes attached to a Y connector to allow for the 2 precursor agents to mix while being injected. The APS polymerizes into a solid spacer within 10 seconds following injection and is said to maintain its structure for 3 months before it starts to slowly hydrolyze and is cleared from the body via the kidneys, with only traces remaining by 6 months.

Controversy: The current standard care during radiation therapy (RT) for PCa is to conduct treatment without a spacer. Dose escalation in selected patients with PCa is well established, with improved local control, biochemical outcomes, and disease-free survival with doses above 70 grays (Gy). However, the location of the prostate gland in front of the rectum increases the potential vulnerability of this organ to clinically important complications from radiation toxicity and thus is a limiting factor in RT treatment protocols for PCa.

Key Questions:

  • Is the SpaceOAR APS effective in preventing rectal toxicity and improving quality of life in patients with PCa undergoing RT?
  • How does the SpaceOAR APS compare with other rectal spacer devices or no spacer?
  • Is the SpaceOAR APS safe for use in patients with PCa undergoing RT?
  • Have definitive patient selection criteria been identified for use of the SpaceOAR APS in patients with PCa undergoing RT?