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Does biodegradable peri-rectal spacer mitigate treatment toxicities in radiation therapy for localised prostate cancer—a systematic review and meta-analysis

Prostate Cancer and Prostatic Diseases volume 28, pages 927–937 (2025)Cite this article

Subjects

Abstract

Introduction

There is an increasing use of biodegradable peri-rectal spacer prior to radiation therapy for prostate cancer to reduce treatment-associated rectal toxicity. While data from individual trials and cohorts is maturing, there is a lack of an updated quantitative analysis that includes outcomes following peri-rectal spacer. We aim to delineate the clinical impact of peri-rectal spacer in localised prostate cancer patients treated with radiotherapy.

Methods

In March 2024, a systematic search was performed on MEDLINE, Embase, and Cochrane Central Register of controlled trials for publications since the year 2010. Prospective and retrospective studies reporting comparative outcomes of patients with and without peri-rectal spacer prior to radiotherapy were considered. Outcomes are reported in binary fashion. Random effect meta-analysis with the use of weighted mean difference was adopted. Early (≤3 months) and late rectal toxicity stratified according to the Common Terminology Criteria for Adverse Events (CTCAE) criteria, early and late genitourinary toxicity, quality of life in bowel, sexual and urinary domains (in terms of minimal clinically important difference) were assessed.

Results

The systematic review included 17 studies. There are 3 RCTs, 3 prospective cohorts, and 11 retrospective cohorts. Three thousand two hundred patients were included, with 1471 patients who received peri-rectal spacer and 1729 without. The use of spacer is associated with lower likelihood of late (1.62% vs. 9.35%, RR = 0.25, 95% CI = 0.15–0.42, P < 0.001) and early grade 2 or above late rectal toxicity (3.07% vs. 6.05%, RR = 0.53, 95% CI = 0.33–0.86, P < 0.001). No difference is observed in significant grade 3 or above GI (acute or late) events. There is no statistical difference in bowel-related bowel QoL (risk difference = −0.16, 95% CI = −0.38–0.06, P = 0.15). The perirectal spacer is not associated with negative impact to urinary or sexual domains of QoL either.

Conclusion

In localised prostate cancer patients treated with radiation therapy, the use of peri-rectal spacer is associated with reduced rectal toxicities.

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Fig. 1: PRISMA flow chart of the current study.
Fig. 2: Forrest plots of outcomes related to rectal toxicities of spacer versus control.
Fig. 3: Forrest plots of subgroup analysis of grade 2 or above rectal toxicities according to spacer types.
Fig. 4: Minus-one-study sensitivity analysis on late grade 2 or above rectal toxicities.

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Authors and Affiliations

  1. S.H. Ho Urology Centre, Department of Surgery, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China

    Chris Ho-Ming Wong, Ivan Ching-Ho Ko, David Ka-Wai Leung, Steffi Kar-Kei Yuen, Brian Siu & Jeremy Yuen-Chun Teoh

  2. Department of Medicine, London Health Science Center, London, ON, Canada

    Cathy Yuan

  3. Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, China

    Jeremy Yuen-Chun Teoh

  4. Department of Urology, Medical University of Vienna, Vienna, Austria

    Jeremy Yuen-Chun Teoh

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Chris Ho-Ming Wong was responsible for the conceptualisation of the study, methodology design, and writing of the manuscript. Ivan Ching-Ho Ko was responsible for the data collection, analysis, and draughting of the manuscript. David Ka-Wai Leung was responsible for the data analysis, interpretation, and critical revision of the manuscript. Steffi Kar-Kei Yuen was responsible for the data validation and contributed to manuscript preparation. Brian Siu assisted in manuscript screening and extraction. Cathy Yuan provided resources and contributed to methodology, analysis, and the review of the manuscript. Jeremy Yuen-Chun Teoh was responsible for the supervision, funding acquisition, project administration, and final approval of the manuscript.

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Correspondence to Jeremy Yuen-Chun Teoh.

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Wong, C.HM., Ko, I.CH., Leung, D.KW. et al. Does biodegradable peri-rectal spacer mitigate treatment toxicities in radiation therapy for localised prostate cancer—a systematic review and meta-analysis. Prostate Cancer Prostatic Dis 28, 927–937 (2025). https://doi.org/10.1038/s41391-025-00961-0

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