3204 - Intermediate Term Urinary Outcomes Following Prostate Radiation Therapy after Neoadjuvant Prostate Artery Embolization

V. M. Khatri¹, A. Garg², R. Thapa³, K. Yamoah¹, G. D. Grass¹, and N. Parikh⁴; ¹H. Lee Moffitt Cancer Center and Research Institute, Department of Radiation Oncology, Tampa, FL, ²University of South Florida Morsani College of Medicine, Tampa, FL, ³Moffitt Cancer Center, Tampa, FL, ⁴H. Lee Moffitt Cancer Center and Research Institute, Department of Radiology, Tampa, FL

Purpose/Objective(s): To determine durability of clinical improvement after neoadjuvant prostate artery embolization (PAE) prior to definitive prostate radiotherapy (RT) for localized prostate cancer (PCa). Materials/

Methods: Patients undergoing neoadjuvant PAE for lower urinary tract symptom (LUTS) improvement prior to definitive RT from 2017-2023 were identified from a prospectively maintained database. IPSS scores were prospectively collected at consultation and each follow-up. IPSS scores were categorized as mild (0-10), moderate (11-20), or severe (= 21). IPSS/Quality of Life (QoL) scores and PSA/prostate volume (PV) reduction were compared to baseline/pre-PAE using paired T-test or Wilcoxon signed rank test. Acute and late (>3 months) gastrointestinal (GI) and urinary (GU) toxicities were prospectively collected and graded according to CTCAE v5.0.
Results: 61 patients received PAE prior to RT. Median follow-up was 21.4 months (range 3.5-71.1). One patient had low risk disease (2%), 19 (31%) favorable intermediate risk, 18 (29%) unfavorable intermediate risk, 17 (28%) high or very high risk, and 6 (10%) regional or metastatic disease. Median baseline PV was 90 cc (range 14-240) and median baseline IPSS was 18 points (range 2-34). Prior alpha blocker use was reported in 37 (61%) patients and 35 (57%) received androgen deprivation. Median time from PAE to RT was 14.7 weeks (range 5.3-74.9). Mean IPSS and QoL scores before and after RT are listed in the table. Pre-RT and post-RT IPSS changes did not significantly differ between pre-PAE IPSS severity groups (mild, moderate, severe) or pre-PAE size groups (< 60 cc v = 60) at any time point. Median PV reduction was 26.4 cc or 31.4%. PV reduction was significantly associated with ADT use (mean difference 38.5 cc (35%) with ADT v 18.9 cc (26%) without ADT, p=.003). No local recurrences occurred. Acute grade 2 (G2) GU and GI toxicity were 44% and 13% respectively; late grade 2 and greater GU and GI toxicity was 20% and 9%, respectively. No grade 4 or 5 toxicity occurred.
Conclusion: Neoadjuvant PAE prior to RT provides durable LUTS improvement that is sustained in the intermediate term after RT and reduces the risk of functional GU decline for men with large prostates and/or high baseline LUTS. Prospective investigation is warranted to validate these findings.

Abstract 3204 – Table 1

Mean IPSS Scores
Time Point	IPSS vs Baseline	IPSS vs Post-PAE/pre-RT	QoL vs Baseline	QoL vs Post-PAE/pre-RT
Post-PAE/pre-RT	-10.5 (p<0.0001, n=57)		-2 (p<0.0001, n=55)
3 months post-RT	-8.8 (p<0.0001, n=45)	+2.3 (p=0.001)	-1.8 (p<0.0001, n=28)	+0.1 (NS)
6 months	-8.5 (p<0.0001, n=42)	+1.5 (p=0.04)	-1.4 (p<0.0001, n=22)	+0.5 (p=0.02)
12 months	-9.7 (p<0.0001, n=38)	+0.8 (NS)	-1.9 (p=0.004, n=13)	+0 (NS)
18 months	-9.4 (p<0.0001, n=25)	+2.1 (NS)	+0.2 (NS, n=5)	+1.2 (NS)
24 months	-9.5 (p=0.0002, n=16)	+2.3 (p=0.02)	-1.6 (NS, n=8)	+1.1 (p=0.03)