Clinical Scorecard: Systematic Review of Rectal Spacers Utilizing Polyethylene Glycol Hydrogel in Prostate Brachytherapy Techniques

At a Glance

Key Highlights

• PEG hydrogel spacers (SpaceOAR or DuraSeal) effectively increase prostate-rectum separation, reducing rectal radiation dose during brachytherapy.
• Use of PEG hydrogel spacers is associated with reduced acute and late gastrointestinal toxicity compared to no spacer.
• Spacer insertion is performed transperineally under ultrasound guidance, posterior to Denonvilliers' fascia and anterior to the rectal wall.

Guideline-Based Recommendations

Diagnosis

• Identify prostate cancer patients planned for brachytherapy who may benefit from rectal dose reduction.

Management

• Use PEG hydrogel spacers to increase prostate-rectum distance during prostate brachytherapy to reduce rectal radiation exposure.
• Administer antibiotic prophylaxis as per institutional protocols prior to spacer insertion.
• Perform spacer insertion immediately after brachytherapy procedure under ultrasound guidance in dorsal lithotomy position.

Monitoring & Follow-up

• Monitor for procedure-related complications and gastrointestinal toxicity using established grading systems (e.g., RTOG).
• Assess spacer resorption and rectal spacing duration post-procedure; PEG hydrogel typically resorbs over weeks to months.

Risks

• Potential procedure-related complications including infection, bleeding, or spacer insertion failure.
• No reduction in urethral radiation dose or genitourinary toxicity with PEG hydrogel spacers.

Patient & Prescribing Data

671 patients receiving prostate brachytherapy with PEG hydrogel spacer; 537 controls without spacer

PEG hydrogel spacers used in both salvage and definitive prostate brachytherapy; associated with improved rectal dosimetry and reduced GI toxicity.

Clinical Best Practices

• Use ultrasound guidance with sagittal view to position needle between mid gland and apex of prostate, posterior to Denonvilliers' fascia.
• Administer appropriate antibiotic prophylaxis and preoperative enema as per center protocols to reduce infection risk.
• Perform brachytherapy first, then insert PEG hydrogel spacer immediately after to maximize procedural efficiency.
• Use the 18-gauge needle provided in SpaceOAR kits or 16-18 gauge peripheral venous catheter for spacer injection.
• Employ floor-mounted stepper to stabilize ultrasound probe and free operator’s hands during spacer insertion.

References

• Prostate brachytherapy and PEG hydrogel spacer systematic review