Biodegradable spacer insertion to reduce rectal toxicity during radiotherapy for prostate cancer

Biodegradable spacer insertion to reduce rectal toxicity during radiotherapy for prostate cancer

The National Institute for Clinical Excellence (NICE), have issued evidence based recommendations on biodegradeable spacer insertion to reduce rectal toxicity during radiotherapy for prostate cancer in adults.

This involves using a liquid gel or a balloon to increase the distance between the prostate and the rectum to reduce the amount of radiation reaching the rectum.

Indications and current treatments

Current treatment options for localised or locally advanced prostate cancer include ‘watchful waiting’, active surveillance, radiotherapy, radical prostatectomy, cryotherapy, high-intensity focused ultrasound, androgen deprivation therapy and chemotherapy.

Radiotherapy is an established curative treatment and can be either external-beam radiotherapy or brachytherapy. Brachytherapy can be given at either low- or high-dose rates. Low-dose-rate brachytherapy may be used alone or in combination with external-beam radiotherapy.

The procedure

Radiotherapy for prostate cancer can cause rectal damage because of the close proximity of the prostate to the rectum. Symptoms include diarrhoea, incontinence, proctitis and ulceration of the rectal mucosa. Injecting a biodegradable substance (examples include polyethylene glycol hydrogel, hyaluronic acid and human collagen), or inserting and inflating a biodegradable balloon spacer, in the space between the rectum and prostate is done to temporarily increase the distance between them. The aim is to reduce the amount of radiation delivered to the rectum, and reduce the toxicity to the rectum during prostate radiotherapy.

The procedure is usually done with the patient under general anaesthesia. However, it may be done using local or spinal anaesthesia, depending on local protocols. The patient is placed in the dorsal lithotomy position. With gel injection, a needle is used to insert the gel into the space between the prostate and the rectum using a transperineal approach and transrectal ultrasound guidance. The prostate and the rectal wall are separated using hydrodissection with saline. Once the correct positioning of the needle is confirmed, the biodegradable spacer substance is injected as liquid into the perirectal space. It then polymerises with the saline to form a soft absorbable mass. The spacer degrades slowly over several months. With balloon spacer insertion, a small perineal incision is typically used to insert a dilator and introducer sheath. Using ultrasound guidance, the dilator is advanced towards the prostate base over the needle, which is then removed. A biodegradable balloon is introduced through the introducer sheath and is filled with saline and sealed with a biodegradable plug. The balloon spacer degrades over several months.

Efficacy

This section describes efficacy outcomes from the published literature that NICE have considered as part of the evidence about this procedure.

Only evidence on CE-marked spacers has been considered and these have only been issued with studies of external-beam radiotherapy.

For further evidence on efficacy of biodegradable spacer insertion click here.

Safety

Click here to see safety outcomes from published literature that NICE have considered as part of the evidence about biodegradable spacer insertion.

Information for patients

This procedure works well for reducing rectal toxicity during radiotherapy for prostate cancer and there are no serious concerns about its safety.

Radiotherapy can be used to treat prostate cancer, but sometimes it can irritate and damage part of the patient’s bowel that lies near the prostate. This can cause side effects such as bowel ulceration, bleeding, diarrhoea and incontinence. In this procedure, an absorbable liquid gel is injected, or a balloon is inserted, into the space between the prostate and the rectum, increasing the distance between them. The aim is to reduce the amount of radiation reaching the rectum, so reducing the risk of side effects there.

NHS Choices may be a good place to find out more. NICE’s information on interventional procedures guidance has more about what a procedure is and how we assess them.

Is this procedure right for me?

If you’ve been offered this procedure, your healthcare professionals should discuss with you what is involved, and tell you about the risks and benefits. They should talk with you about your options, and listen carefully to your views and concerns. Your family can be involved too, if you wish. All of this should happen before you agree (consent) to have the procedure. You should also be told how to find more information about the procedure. Read more about making decisions about your care.

Some questions to think about

  • What does the procedure involve?
  • What are the possible benefits? How likely am I to get them?
  • What are the risks or side effects? How likely are they?
  • What happens if the procedure doesn’t work or something goes wrong?
  • What happens if I don’t want the procedure? Are there other treatments available?

 

This information has been provided by the National Institute for Clinical Excellence (NICE).
Interventional procedures guidance [IPG590]
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