{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T20:39:23Z","timestamp":1792615163203,"version":"4.5.0"},"reference-count":28,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T00:00:00Z","timestamp":1790035200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Oncol."],"abstract":"<jats:p>Prostate cancer is one of the most commonly diagnosed cancers in men worldwide. Radiation therapy is a widely used treatment for prostate cancer, but it carries the risk of adverse effects on adjacent organs such as the rectum. Therefore, to provide additional protection for the rectum during prostate radiation, perirectal spacers are inserted into Denonvilliers\u2019 space, the thin fascial layer located behind the prostate gland and in front of the anterior rectal wall. Polyethylene glycol (PEG)-based hydrogels and recently FDA-approved stabilized hyaluronic acid (sHA) spacers have been designed to create a biodegradable space between the prostate and rectum, with each having its own unique characteristics and both having the potential to infiltrate the rectum. We present two clinical cases of rectal infiltration associated with either the insertion of a PEG-based hydrogel or an sHA spacer. Due to the distinct characteristics of the two spacer types, rectal infiltration was managed with either a conservative or definitive approach. With the PEG-based hydrogel, we implemented conservative management with antibiotics and close monitoring. In sharp contrast, for the sHA spacer, we proactively reversed the infiltration with hyaluronidase (Hyal) prior to starting radiation. These cases illustrate the clinical utility of these management approaches and contribute to the growing body of evidence on the management of potential complications associated with perirectal spacers, potentially supporting the use of newer spacer technologies.<\/jats:p>","DOI":"10.3389\/fonc.2026.1885291","type":"journal-article","created":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T05:40:00Z","timestamp":1790055600000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Case Report: Outpatient management of rectal infiltration by iodinated polyethylene glycol hydrogel and stabilized hyaluronic acid spacers in patients with prostate cancer"],"prefix":"10.3389","volume":"16","author":[{"given":"Jessica T.","family":"Lee","sequence":"first","affiliation":[{"name":"University of Hawaii Cancer Center","place":["Honolulu, HI, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Brian C. T.","family":"Pien","sequence":"additional","affiliation":[{"name":"Department of Medicine, John A. Burns School of Medicine, University of Hawaii","place":["Honolulu, HI, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andy K.","family":"Chon","sequence":"additional","affiliation":[{"name":"Department of Radiology, Hawaii Pacific Health","place":["Honolulu, HI, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert F.","family":"Wong","sequence":"additional","affiliation":[{"name":"Pacific Endoscopy Center","place":["Pearl City, HI, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John L.","family":"Lederer","sequence":"additional","affiliation":[{"name":"University of Hawaii Cancer Consortium","place":["Honolulu, HI, United States"]},{"name":"Cancer Center of Hawaii","place":["Honolulu, HI, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,22]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1200\/jco.18.01097","article-title":"Hypofractionated radiation therapy for localized prostate cancer: An ASTRO, ASCO, and AUA evidence-based guideline","volume":"36","author":"Morgan","year":"2018","journal-title":"J Clin Oncol"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.4103\/jcrt.jcrt_846_24","article-title":"Acute toxicity of moderate hypofractionated radiotherapy in localized carcinoma prostate: An observational study","volume":"21","author":"Paskalice","year":"2025","journal-title":"J Cancer Res Ther"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1016\/j.euf.2017.10.011","article-title":"Conventional versus hypofractionated radiation therapy for localized prostate cancer: A meta-analysis of randomized noninferiority trials","volume":"5","author":"Royce","year":"2019","journal-title":"Eur Urol Focus"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijrobp.2015.04.030","article-title":"Hydrogel spacer prospective multicenter randomized controlled pivotal trial: Dosimetric and clinical effects of perirectal spacer application in men undergoing prostate image guided intensity modulated radiation therapy","volume":"92","author":"Mariados","year":"2015","journal-title":"Int J Radiat Oncol Biol Phys"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1001\/jamaoncol.2022.7592","article-title":"Hyaluronic acid spacer for hypofractionated prostate radiation therapy: A randomized clinical trial","volume":"9","author":"Mariados","year":"2023","journal-title":"JAMA Oncol"},{"key":"B6","doi-asserted-by":"publisher","first-page":"94","DOI":"10.1016\/j.urology.2023.12.034","article-title":"Major complications and adverse events related to use of SpaceOAR hydrogel for prostate cancer radiotherapy","volume":"188","author":"Millot","year":"2024","journal-title":"Urology"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1021\/bm100137q","article-title":"Hydrolytically degradable poly(ethylene glycol) hydrogel scaffolds with tunable degradation and mechanical properties","volume":"11","author":"Zustiak","year":"2010","journal-title":"Biomacromolecules"},{"key":"B8","doi-asserted-by":"publisher","first-page":"297","DOI":"10.5999\/aps.2020.00752","article-title":"Hyaluronidase: An overview of its properties, applications, and side effects","volume":"47","author":"Jung","year":"2020","journal-title":"Arch Plast Surg"},{"key":"B9","first-page":"1","article-title":"Next-generation hydrogel spacer launches in US urology market","volume":"48","author":"Broderick","year":"2020","journal-title":"Urol Times"},{"key":"B10","volume-title":"De Novo Classification Request for Spaceoar System. 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