Urinary Outcomes for Men with High Baseline International Prostate Symptom Scores Treated with Prostate SBRT

Abstract Background There are limited data regarding high-dose stereotactic body radiation therapy (SBRT) for prostate cancer in patients with poor baseline urinary function. The purpose of this study was to evaluate genitourinary (GU) toxicity and changes in patient reported symptom severity scores after prostate SBRT in men with high pre-treatment International Prostate Symptom Scores (IPSS). Methods 753 patients treated with prostate SBRT at our institution from 2012-2019 were identified, of which 72 consecutive patients with baseline IPSS ≥15 were selected for this study. GU toxicity according to CTCAE v3.0 and IPSS were prospectively documented at each follow-up visit. Univariable logistic regression was used to evaluate for potential predictors of GU toxicity. Results Median follow-up in survivors was 26.8 months. The rates of acute grade 2 and 3 GU toxicity were 20.8% and 1.4%, respectively. The rates of late grade 2 and 3 GU toxicity were 37.5% and 5.6%, respectively. The majority of grade 2+ toxicities resolved by last follow-up and when toxicities were re-graded per CTCAE v5.0, there were no longer any grade 3 adverse events. Total IPSS and individual symptom sub-scores improved over time. Compared to baseline, median total IPSS at 24 +/- 6 months was significantly lower (18 vs 12, p Conclusions In men with baseline IPSS ≥15 managed with prostate SBRT, the rate of severe GU toxicity was low and patient reported symptoms generally improved over time. Thus, high pre-treatment IPSS should not deter clinicians from offering prostate SBRT.