Prostatic Urethral Length on MRI Potentially Predicts Late Genitourinary Toxicity After Radiation For Prostate Cancer

Document Type

Conference Proceeding

Publication Date

5-2024

Publication Title

Journal of Urology

Abstract

INTRODUCTION AND OBJECTIVE: To evaluate pretreatment prostate quantitative magnetic resonance imaging (MRI) measurements and clinical characteristics for predicting genitourinary (GU) toxicity after radiotherapy (RT) for prostate cancer (PCa). METHODS: In a single institution, retrospective cohort study, we evaluated patients with PCa who had MRI within 6 months of RT from June 2016 to February 2023. MRI measurements included quantitative urethra, prostate, and bladder measurements. The Common Terminology Criteria for Adverse Events (CTCAE v4.0) was used with late toxicity defined as >180 days. Univariable and multivariable Cox proportional hazard models were used for late toxicity, adjusted for clinical factors and RT method. RESULTS: A total of 361 men (median age 68 years, inter-quartile range (IQR) 62-73) were included. Rates of grade ≥2 GU toxicity were 11.3%, 23.6%, and 28% at year 1, 2, and 3, respectively. Prostatic urethral length had a median of 4.6cm with an IQR of 4.1-5.1cm. Only longer prostatic urethral length (hazard ratio (HR):1.6, 95%CI: 1.2-2.1, p p<0.01) was associated with increased risk of late GU toxicity, notably urinary frequency/urgency symptoms (HR: 1.7 (95%CI:1.3-2.3), p<0.01). Of note, pretreatment AUA score was not statistically significant. CONCLUSIONS: Longer prostatic urethral length measured on prostate MRI is independently associated with higher risk of developing late grade ≥2 GU toxicity after radiation therapy for PCa. This pre-treatment metric may be potentially valuable in risk-stratification models for patients considering radiation therapy vs prostatectomy.

Volume

211

Issue

5S

First Page

e1208

Comments

American Urological Association Annual Meeting, May 3-6, 2024, San Antonio, TX

DOI

10.1097/01.JU.0001008808.16085.aa.01

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