SpaceOAR prior to Radiotherapy or Cyberknife (H4685)
Radiation therapy uses focused beams of intense energy to destroy cancer cells and shrink or control the growth of tumours. Radiation therapy works by preventing targeted cells from multiplying. The objective of radiation therapy is to destroy the harmful cells while minimizing damage to healthy cells.
Radiosurgery is a form of radiation therapy that uses precisely targeted radiation to destroy tumours. Radiosurgery is non-invasive – there is no cutting involved. The term "surgery" refers to the high level of precision of the energy beams.
Stereotactic body radiation therapy (SBRT) is a treatment that uses precisely targeted radiation to destroy tumours located outside the brain and spine.
The CyberKnife System is a unique, robotic system designed to deliver high-precision radiosurgical and SBRT procedures.
SpaceOAR is a system that works by placing a small amount of gel between the prostate and rectum, a prostate spacer, to increase the distance between them, thus reducing the radiation dose received by the rectum during treatment. The SpaceOAR system is composed of biodegradable material that can maintain the space between the rectum and prostate through the entire course of radiotherapy and is absorbed by the patient’s body over time.
SpaceOAR hydrogel provides up to 1.2 cm of space between the rectum and the prostate, reducing high dose radiation to the rectum.
Why this procedure
Radical prostatectomy and prostate radiotherapy have been shown to be the two most successful treatments for low and intermediate grade prostate cancer. Historically the most common complications following radical prostatectomy were related to urinary system injury (incontinence, erectile dysfunction), while complications following prostate radiotherapy were often related to rectal radiation injury (bleeding, diarrhoea). Now a new technology called SpaceOAR hydrogel is available that reduces rectal injury during prostate radiotherapy, potentially simplifying the decision process for patients deciding which treatment to undergo.
Rectal injury can occur during prostate cancer radiation treatment because the rectum sits next to the prostate and can consequently receive high radiation doses. To reduce this injury, SpaceOAR hydrogel physically pushes the rectum away from the prostate during treatment thereby reducing both the rectal radiation dose and side effects.
After radiation treatment is over the hydrogel completely absorbs, leaving nothing behind.
What is the procedure
Using ultrasound guidance, the hydrogel is administered as a liquid that expands the space between Denonvilliers’ fascia (the structure that separates the prostate and urinary bladder from the rectum) and the rectal wall, where it solidifies into a soft, but firm, hydrogel within 10 seconds. The hydrogel remains in place for 3 months during prostate radiotherapy, after which it liquefies by hydrolysis, and is absorbed and cleared in the patient’s urine.