Ejaculatory Function Following Stereotactic Body Radiation Therapy for Prostate Cancer

Background: Ejaculatory dysfunction is an important male quality of life issue which has not yet been studied in the setting of prostate stereotactic body radiation therapy (SBRT). Aim: The purpose of this study is to evaluate ejaculatory function following SBRT for prostate cancer. Methods: Two hundred and thirty-one patients on a prospective quality of life study with baseline ejaculatory capacity treated with prostate SBRT from 2013 to 2019 were included in this analysis. Ejaculation was assessed via the Ejaculation Scale (ES-8) from the Male Sexual Health Questionnaire. Patients completed the questionnaire at 1, 3, 6, 9, 12, 18, and 24 months post-SBRT. Elderly patients (Age > 70) and those who received hormonal therapy were excluded from analysis. Patients were treated to 35-36.25 Gy in 5 fractions delivered with the CyberKnife Radiosurgical System (Accuray). Outcomes: Ejaculatory function was assessed by ES-8 scores (range 4-40) with lower values representing increased interference or annoyance. Results: Median age at the time of treatment was 65 years. Median follow up was 24 months (IQR 1924.5 months). 64.5% of patients had ED at baseline (SHIM < 22). The 2-year anejaculation rate was 15%. Mean composite ES-8 scores showed a decline in the first month following treatment then stabilized: 30.4 (start of treatment); 26.5 (1 month); 27.6 (3 month); 27.0 ( 6 month); 26.2 (9 month); 25.4 (12 month); 25.0 (18 month) and 25.4 (24 month). White race, higher pre-treatment SHIM (>= 22), and higher ES-8 (>= 31) at treatment start were significantly associated with a decreased probability of a clinically significant decline. Patient-reported ejaculate volume was significantly reduced at all time points postSBRT. Ejaculatory discomfort peaked at 1 month and 9 months post-SBRT. Prior to treatment, 8.0% of men reported that they were very to extremely bothered by their ejaculatory dysfunction. The number of patients reporting this concern increased to 14.4% at one year and dropped to 11% at 24-months postSBRT. Clinical Translation: Patients undergoing prostate SBRT may experience meaningful changes in ejaculatory function and should be counseled on the trajectory of these side effects. Strengths & Limitations: This was a retrospective analysis of a prospectively maintained database. Subjective questionnaire responses captured limited aspects of ejaculatory function in this cohort. Conclusion: The high incidence of moderate to extreme bother in ejaculatory function before and after SBRT suggests a need for novel approaches to improving ejaculation. Copyright (C) 2022, International Society of Sexual Medicine. Published by Elsevier Inc. All rights reserved.