Pd15-11 efficacy and safety of biodegradable rectal spacer balloon in patients receiving prostate imrt: an international phase 3 randomized trial

You have accessJournal of UrologyCME1 Apr 2023PD15-11 EFFICACY AND SAFETY OF BIODEGRADABLE RECTAL SPACER BALLOON IN PATIENTS RECEIVING PROSTATE IMRT: AN INTERNATIONAL PHASE 3 RANDOMIZED TRIAL Daniel Song, Mateusz Dabkowski, Warsaw Poland, Paulo Costa, Rizwan Nurani, Michael Kos, Ben Vanneste, David Margel, Eli Sapir, Shawn Zimberg, Oleksandr Boychak, Edward Soffen, Abdulla Alhasso, Kenneth Tokita, Dian Wang, Zvi Symon, and Richard Hudes Daniel SongDaniel Song More articles by this author , Mateusz DabkowskiMateusz Dabkowski More articles by this author , Warsaw PolandWarsaw Poland More articles by this author , Paulo CostaPaulo Costa More articles by this author , Rizwan NuraniRizwan Nurani More articles by this author , Michael KosMichael Kos More articles by this author , Ben VannesteBen Vanneste More articles by this author , David MargelDavid Margel More articles by this author , Eli SapirEli Sapir More articles by this author , Shawn ZimbergShawn Zimberg More articles by this author , Oleksandr BoychakOleksandr Boychak More articles by this author , Edward SoffenEdward Soffen More articles by this author , Abdulla AlhassoAbdulla Alhasso More articles by this author , Kenneth TokitaKenneth Tokita More articles by this author , Dian WangDian Wang More articles by this author , Zvi SymonZvi Symon More articles by this author , and Richard HudesRichard Hudes More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003262.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Rectal gel spacers have been shown to reduce rectal side effects in patients receiving prostate radiation. However, concerns remain regarding precise and reproducible gel injection. We report on a novel rectoprostatic spacer balloon which allows potential for controlled, adaptable deployment without time constraints associated with hydrogel injection. To determine efficacy and safety, the study had co-primary hypotheses: 1) Balloon spacer would result in ≥25% reduction of rectal V70 in >75% of subjects, and 2) Implantation procedure-related and rectal ≥ Grade 1 adverse events would be non-inferior in balloon vs control subjects (events with duration ≥2 days within 6 months, CTCAE 4.0). METHODS: 222 subjects were enrolled at 16 centers. All patients had biopsy-proven T1-T3 prostate cancer without MRI evidence of posterior extraprostatic invasion. Patients receiving brachytherapy or whole pelvic RT were excluded. Randomization was 2:1 (balloon:control) and subject-blinded. All patients underwent transperineal TRUS-guided fiducial marker placement±biodegradable balloon, followed by IMRT. For efficacy endpoint comparisons, plans were generated by central core lab on pre- and post-implant CT scans (81 Gy in 1.8 Gy fractions). Adverse events were reviewed by blinded, independent Clinical Events Committee. RESULTS: The primary efficacy endpoint was met, with 97.9% of balloon subjects (139/142) having rectal V70 reduction of >25% (pre- vs post-implant; p<0.001, 95% CI (94.0, 99.6%). Mean V70 was 7.0 % pre- vs 1.1% post-implant. Similar decreases were observed in rectal V40–V80. Mean prostate-rectal spacing achieved (19+3.7mm) was maintained through radiation treatment (18+3.9mm). Balloon placement was successful in 99% of subjects. The primary safety endpoint was met with balloon subjects experiencing fewer ≥ Grade 1 events, 18% vs 23% (p<0.001, 95% CI -15.7%, 5.5%). Event rate was higher in balloon subjects in early post-implant period, but control arm surpassed balloon group at/beyond day 44 post-implant. On pre-defined secondary endpoint of ≥Grade 2 events, rates were lower in balloon subjects (4.3% vs 6.5%). Complete balloon resorption was observed on 6-month CT in 98.5% (133/135) of subjects. CONCLUSIONS: Biodegradable rectal spacer balloon was effective in significantly reducing dose to rectum, and associated with decreased cumulative rectal plus implantation-related adverse events. Balloon resorption was consistently observed by 6 months. Source of Funding: BioProtect, Ltd © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e423 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Daniel Song More articles by this author Mateusz Dabkowski More articles by this author Warsaw Poland More articles by this author Paulo Costa More articles by this author Rizwan Nurani More articles by this author Michael Kos More articles by this author Ben Vanneste More articles by this author David Margel More articles by this author Eli Sapir More articles by this author Shawn Zimberg More articles by this author Oleksandr Boychak More articles by this author Edward Soffen More articles by this author Abdulla Alhasso More articles by this author Kenneth Tokita More articles by this author Dian Wang More articles by this author Zvi Symon More articles by this author Richard Hudes More articles by this author Expand All Advertisement PDF downloadLoading ...