What is SpaceOAR™ Hydrogel?
SpaceOAR Hydrogel is an absorbable hydrogel that temporarily creates space between the prostate and the rectum, reducing the radiation dose delivered to the rectum during prostate radiation therapy.
When treating prostate cancer patients with radiation therapy, the goal is to kill the cancer cells while avoiding damage to surrounding healthy tissue. The prostate is next to the rectum and naturally separated by a small space. Due to the proximity, prostate radiation therapy can unintentionally cause damage to the rectum, which can lead to issues with bowel function. The “OAR” in SpaceOAR stands for “organ at risk,” and with radiation therapy to the prostate, this organ is the rectum.
By acting as a spacer, the hydrogel temporarily moves the rectum a half inch (1.3 cm) away from the prostate.¹ By separating the prostate from the rectum, SpaceOAR Hydrogel reduces the radiation dose delivered to the rectum and may eliminate or decrease damage.
SpaceOAR Hydrogel is made up of two liquids that when combined form a soft gel material that is mostly made of water. The material that the SpaceOAR Hydrogel is made from has been used in other implants such as surgical sealants used in the eye, brain, and spine.
SpaceOAR Hydrogel can be implanted as an outpatient procedure in a hospital, surgery center, outpatient clinic or doctor’s office prior to the start of radiation treatment. It is typically not a lengthy procedure.
SpaceOAR is intended to temporarily position the anterior rectal wall away from the prostate during radiotherapy for prostate cancer and in creating this space it is the intent of SpaceOAR hydrogel to reduce the radiation dose delivered to the anterior rectum. The SpaceOAR hydrogel is composed of biodegradable material and maintains space for the entire course of prostate radiotherapy treatment. It is completely absorbed by the patient’s body over time.
Clinical data comparing patients with and without SpaceOAR hydrogel demonstrated the benefits of SpaceOAR hydrogel to include reduction of rectal toxicity resulting in improved bowel function, improvements in urinary function, and a higher likelihood to maintain sexual function.
Potential complications associated with SpaceOAR hydrogel include but are not limited to pain associated with SpaceOAR hydrogel injection; pain or discomfort associated with SpaceOAR hydrogel, needle penetration of the bladder, prostate, rectal wall, rectum, or urethra; injection of SpaceOAR hydrogel into the bladder, prostate, rectal wall, rectum, or urethra; local inflammatory reactions; infection; injection of air, fluid or SpaceOAR hydrogel intravascularly; urinary retention; rectal mucosal damage, ulcers, necrosis; bleeding; constipation; and rectal urgency.
1. 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
2. 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)