Hydrogel Perirectal Spacer for Prostate Cancer Radiotherapy
A hydrogel perirectal spacer is a gel that’s injected into the space between the prostate and the rectum. It’s used to gently separate these structures so that radiotherapy can be delivered to the prostate, while reducing exposure to the surrounding healthy tissue.
What is a hydrogel perirectal spacer?
Prostate cancer is the most common male cancer in the UK, with tens of thousands of new diagnoses every year. Radiotherapy is a highly effective treatment, but because the prostate lies very close to the rectum, bladder, and nerves involved in sexual function, these structures can be affected by treatment.
A hydrogel perirectal spacer, often referred to by the brand name SpaceOAR®, is a soft gel that’s injected between the prostate and rectum. This creates around 1cm of space, which acts as a temporary cushion during prostate cancer radiotherapy. The additional distance helps shield the rectum from unnecessary radiation exposure.
Placing a hydrogel spacer can significantly reduce the risk of long-term radiotherapy-related side effects such as rectal pain, bowel urgency, bleeding, urinary leakage and, in some cases, erectile dysfunction. The gel stays in place throughout the course of radiotherapy and is naturally broken down by the body after around 3 months.
At Welbeck, our urologists are highly experienced in using hydrogel spacers to support safe and effective prostate cancer radiotherapy. Our consultants use the SpaceOAR® system — the most widely researched spacer, backed by a large clinical trial and more than 250,000 implants worldwide. Studies show it can reduce radiation to the rectum and lower the risk of long-term side effects by over 70%.
Your treatment will take place in our dedicated Men’s Health centre, where comfort and state-of-the-art facilities come together to support your care. You’ll leave feeling well-prepared and confident as you move forward with safer, more targeted radiotherapy.
More information
The treatment is minimally invasive and usually takes less than 20 minutes to complete as a day-case procedure. Most patients have it under local anaesthetic, but general anaesthetic or sedation can be used if preferred, or more suitable for you.
During the procedure:
You’ll lie comfortably while the area is cleaned and prepared.
Anaesthetic is used to numb the region.
Using ultrasound guidance, your consultant will insert a fine needle between the prostate and rectum.
The hydrogel is injected, gently filling the space and creating a soft, protective barrier.
Once the gel is in position, imaging may be carried out to check the placement, and then you’ll be able to home when you feel ready.
The gel remains stable throughout your radiotherapy course. After around 3 months, it’s naturally absorbed and removed by the body, without the need for further treatment.
Injecting a hydrogel perirectal spacer is considered very safe, and complications are uncommon. However, as with any medical procedure, there are some risks.
Risks include:
mild pain or discomfort at the injection site
temporary inflammatory reactions
infection
bleeding or bruising
rectal irritation, including constipation, urgency or in rare cases, small ulcers
All of these complications are very rare, affecting less than 3% of all patients, and our team will take every precaution to minimise them.
There’s usually very little you need to do beforehand, but your consultant will give you personalised instructions. These may include stopping certain medications or avoiding food and drink for a short time if you’re having a general anaesthetic.
On the day of the procedure, wear loose, comfortable clothing, and if you’re having a general anaesthetic or sedation, make sure someone is available to take you home afterwards.
Most patients feel well enough to go home shortly after the procedure. Any discomfort from the injection site is usually mild and can be managed with standard pain relief such as paracetamol or ibuprofen.
Some people notice temporary rectal fullness or pressure for a day or so. This should settle quickly. You can return to light activities the same day, although strenuous exercise is best avoided for 24 to 48 hours.
If you experience ongoing pain, fever, worsening bowel symptoms, or concerns about bleeding, you should contact your clinical team for advice.
The gel remains in place until treatment is complete, and then dissolves naturally over the following weeks.
Please contact our Men’s Health centre for pricing.
At Welbeck, our urologists are experts in their field and are dedicated to providing world-class care to every patient.
With access to colleagues across other specialties, our consultants are also able to refer within the Welbeck ecosystem if required to ensure you receive the treatment you need as quickly as possible, all under one roof.
All appointments, testing, treatment, and follow-up appointments take place within our state-of-the-art facilities, enabling us to deliver accurate diagnostics and advanced treatments.
To book a hydrogel perirectal spacer, you must be referred by either your GP or a specialist following a consultation with them. Self-referrals are not accepted for this treatment.
If you would like to schedule a consultation with a specialist, please get in touch to make an appointment. Your health is important to us, so we strive to offer same-day appointments whenever possible.
Our consultants are recognised by the major health insurance companies. If you have private health insurance, your treatment at Welbeck can begin once you have obtained authorisation. We also provide care to self-paying patients. Learn more about the different payment options at Welbeck.
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Frequently asked questions
Most people do not feel the spacer once the initial injection discomfort has worn off. A sense of fullness in the rectum may be noticeable for a day or so, but usually settles quickly.
No. Having a hydrogel spacer will not delay your treatment. At Welbeck, we offer fast access to appointments, so the procedure can be arranged quickly as part of your radiotherapy preparation. Treatment planning can begin straight away, and in many cases, the spacer actually helps streamline radiotherapy by reducing the need for dose adjustments.
No. The spacer does not interfere with the effectiveness of radiotherapy. It simply protects the surrounding tissue, allowing your oncology team to deliver your treatment safely and accurately.
The SpaceOAR Hydrogel is a soft gel material, mostly made of water and polyethene glycol (PEG), which is commonly used in other medical implants. It’s biodegradable and will be naturally absorbed by your body without any side effects.