Rectal spacers move beyond toxicity reduction in prostate radiation

In this interview, Sean P. Collins, MD, PhD, discusses how emerging evidence on rectal spacers is reshaping their role in prostate cancer radiation therapy.

Historically, spacers were used primarily to reduce rectal toxicity by increasing the distance between the prostate and rectum. Collins notes that clinicians typically reserved them for patients at higher risk of bowel side effects or for those especially concerned about toxicity. However, new data presented at the 2025 American Society for Radiation Oncology Annual Meeting suggest that spacers may also enhance cancer control, expanding their clinical value beyond toxicity mitigation.

Collins explains that he now frames the conversation with patients more broadly, emphasizing not only the reduction of bowel urgency and frequency but also the possibility of improving the effectiveness and safety of radiation dose escalation. He highlights innovative uses of spacers, such as positioning them to spare neurovascular bundles, to potentially preserve sexual function. Collins encourages clinicians to think creatively about how this simple, easily placed device can improve multiple dimensions of quality of life.

When counseling patients, Collins stresses the importance of individualized, thorough discussions that outline the risks and benefits of all treatment strategies, including hormones, surgery, radiation, and the use or omission of a spacer. He views the new evidence as an additional talking point that can help patients make informed decisions, especially when higher-dose or lesion-targeted radiation could be delivered more safely with a well-placed spacer.

For practicing urologists, Collins underscores that they remain the first point of contact for most prostate cancer patients and therefore play a key role in patient education. He argues that rectal spacers should no longer be viewed as single-purpose tools. Beyond rectal protection, they may facilitate curative radiation dosing and reduce the likelihood of local recurrence—an important consideration given the challenges of managing patients who require surgery after radiation. Ultimately, he suggests that wider and more strategic use of spacers can improve outcomes for both patients and the clinicians who care for them over the long term.

REFERENCE

1. Collins SP, Tran E, Roane A, Morton R. Real-world data analysis of biochemical recurrence after primary radiotherapy for prostate cancer: Propensity matched comparison of patients with hydrogel rectal spacing vs no spacing. Int J Radiat Oncol Biol Phys. 2025;123(1S):e724-725. Abstract 3599