PD08-12 OUTCOMES AND TOXICITY AFTER PROSTATE SBRT IN MEN WITH VERY LARGE PROSTATE GLANDS (>100 cc) (2021)

You have accessJournal of UrologyProstate Cancer: Localized: Radiation Therapy (PD08)1 Sep 2021PD08-12 OUTCOMES AND TOXICITY AFTER PROSTATE SBRT IN MEN WITH VERY LARGE PROSTATE GLANDS (>100 cc) Jonathan Haas, Christopher Mendez, Matthew Witten, Aaron Katz, Todd Carpenter, Michael Repka, Jonathan Lischalk, Herbert Lepor, Astrid Sanchez, Daniel Haas, and Seth Blacksburg Jonathan HaasJonathan Haas More articles by this author , Christopher MendezChristopher Mendez More articles by this author , Matthew WittenMatthew Witten More articles by this author , Aaron KatzAaron Katz More articles by this author , Todd CarpenterTodd Carpenter More articles by this author , Michael RepkaMichael Repka More articles by this author , Jonathan LischalkJonathan Lischalk More articles by this author , Herbert LeporHerbert Lepor More articles by this author , Astrid SanchezAstrid Sanchez More articles by this author , Daniel HaasDaniel Haas More articles by this author , and Seth BlacksburgSeth Blacksburg More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001976.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Studies have shown that patients treated with conventional radiation can have higher risk of gastrointestinal and genitourinary side effects. There are limited data showing that patients with larger prostate glands greater than 50 cc can safely be treated with Stereotactic Body Radiation Therapy (SBRT) to the prostate. The study reports our experience using SBRT delivered with a robotic linear accelerator for patients with localized prostate cancer having larger prostate gland volumes greater than 100 cc. METHODS: Between 2006 and 2020, 3,393 patients with low and intermediate risk prostate cancer were treated with definitive robotic based SBRT and followed at a large academic practice. 67 patients with prostate volumes greater than or equal to 100 cc were treated and had a minimum of 2 years follow-up. All patients were treated to a dose of 35-36.25 Gray in 5 fractions prescribed to the 83-87% isodose line. Of these, 18 patients received androgen deprivation therapy prior to treatment. All patients in this analysis had a prostate volume greater than 100 cc as the final volume prior to undergoing SBRT regardless of receiving ADT. Biochemical control was assessed using the Phoenix definition. Long-term rectal and urinary toxicity was characterized as occurring > 6 months post treatment. RESULTS: 67 patients (19 low and 48 intermediate risk according to D'Amico classification) were treated. The median age was 70 (range 54 - 87). The median prostate volume was 139.37 (range 100.1 - 227); the median pretreatment PSA was 8.7 ng/ml and decreased to a median PSA of 0.5 at 2 years. Mean baseline EPIC bowel and urinary scores of 87.8 and 79.7 decreased to 83.6 and 76.5 at 1 month. This further decreased to 83.2 and 71.1 at 3 months. This improved by 1 year to 86.16 and 77.19 respectively and by 2 years improved above baseline to 90.00 and 85.78 respectively. The 2-year incidence of grade 1 or 2 GI and GU toxicity was 0% respectively. 1 patient experienced grade 3 urinary toxicity (retention). No patients experienced grade 3 bowel toxicity. The 5 year median PSA was 0.6 and the biochemical relapse free survival was 100% at 5 years. CONCLUSIONS: SBRT using a robotic linear accelerator for clinically localized low and intermediate risk prostate cancer has short term increase in bowel and urinary toxicity in men with very large glands. This resolves by 1 year. SBRT was well-tolerated and efficacious in men with prostate gland volumes greater than 100 cc. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e118-e118 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jonathan Haas More articles by this author Christopher Mendez More articles by this author Matthew Witten More articles by this author Aaron Katz More articles by this author Todd Carpenter More articles by this author Michael Repka More articles by this author Jonathan Lischalk More articles by this author Herbert Lepor More articles by this author Astrid Sanchez More articles by this author Daniel Haas More articles by this author Seth Blacksburg More articles by this author Expand All Advertisement Loading ...