What is SpaceOAR® Hydrogel?

Written by: Mr Neil Haldar
Published: | Updated: 04/10/2019
Edited by: Lisa Heffernan

Men undergoing radiation therapy for prostate cancer can experience some negative side effects, especially regarding bowel function, urination and sexual functioning. Consultant urological surgeon Mr Neil Haldar shares his insight into SpaceOAR hydrogel that protects the rectum during radiation therapy and how it greatly benefits men who need radiation therapy for prostate cancer.

SpaceOAR hydrogel (OAR standing for organ-at-risk, that organ being the rectum) is an absorbable gel inserted between the prostate and rectum to push the rectum away from the radiotherapy field in patients who are going to have radical radiotherapy for prostate cancer.


The gel, once inserted, separates the rectum away from the prostate radiotherapy field, therefore it limits the collateral damage that the radiotherapy could cause the rectum if the gel were not in place. It also allows for a maximum radiation dose to be given to the prostate, while protecting the rectum from any harm.


The gel is made up of two liquid components, that when combined form a soft gel-like synthetic material that is mostly made of water. The gel stays in place for about three months, before being safely reabsorbed back into the body. Reabsorption can take up to six months, well after your last radiation treatment.


How can SpaceOAR® Hydrogel reduce the side effects caused by prostate cancer radiation treatment?


Radiation therapy is highly effective at targeting prostate cancer cells, however, there are potential side effects to this treatment such as:


Studies have shown that SpaceOAR reduces the side effects of radiation therapy by around 70%. The SpaceOAR hydrogel creates a space between the rectum and prostate, so the rectum doesn’t get involved in the radiation field, resulting in fewer side effects and less rectal toxicity.


In the studies, investigators found that three years after prostate radiotherapy those patients who had the SpaceOAR gel inserted prior to treatment reported that:

  • Sexual functioning was better maintained
  • Bowel function was less affected, patients experienced fewer loose stools and less frequent bowel movements
  • Their urinary system was less affected, patients experienced less urgency to urinate and needed to urinate less often


Are there any unpleasant side effects/risks after this treatment?

The only real side effects are some bruising after the procedure at the injection site and the risk of misplacement of the hydrogel into the rectal wall. This can cause discomfort but it’s not dangerous as the gel simply gets reabsorbed back into the body after some time.


More complicated risks are rare but can include rectal wall necrosis, bleeding, urinary retention, inflammatory reactions or needle penetration of the bladder or urethra, for example. Talk these risks over with your doctor if you have any doubts before treatment.


Is the SpaceOAR® Hydrogel suitable for all prostate cancer patients?

SpaceOAR is suitable for patients undergoing external beam or radical radiation therapy. Some patients are not suitable for the treatment if the prostate cancer has become so enlarged that it leaves no space between the prostate and the rectum for the gel to be inserted.


Can SpaceOAR® Hydrogel be used to treat other conditions as well?

At the moment SpaceOAR is just being used to treat prostate cancer, but its use in other conditions is under development.


Do all specialists use this during radiation treatment?

No, not all specialists use this treatment. It’s a new treatment and has only been in the UK for the last 18 months. It was first developed in the United States, before moving to Australia and then onto the UK.


Who offers SpaceOAR® Hydrogel?

Urologists offer the treatment, however, sometimes oncologists can carry out the procedure, although for the most part oncologists ask for the treatment to be done and urologists insert the hydrogel into the patient.


If you or a loved one have been told to undergo radiation therapy, ask your doctor or urologist about SpaceOAR hydrogel before having radiation therapy.



By Mr Neil Haldar

Mr Neil Haldar is a leading consultant urological surgeon based in Buckinghamshire. After graduating from King's College Medical School in 1992 Mr Haldar went on to join the Oxford Junior Surgical training program. From there Mr Haldar was awarded by the Royal College of Surgeons the Allinson Foundation Research Fellowship in which he was able to undertake his Master's degree at the Nuffield Department of Surgery in Oxford. Once he completed his specialty urological training, Mr Haldar became the Clinical Lead in laparoscopic urology at the Buckinghamshire NHS Trust. 

Mr Haldar is well published in most aspects of urology, with a current focus on researching Enhanced Recovery Surgery. Mr Haldar's main clinical specialties include bladder, prostate and kidney cancer. He is also an expert in minimal access surgery and in 2008 was one of the first UK surgeons to perform a single incision transperitoneal and extraperitoneal laproscopic nephrectomy.

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