The impact of patient characteristics on voiding symptoms, irritative symptoms, and sexual function, following stereotactic body radiotherapy for prostate cancer.

Abstract

245 Background: Urinary symptoms and sexual dysfunction are the two most common complaints following prostate radiotherapy. There is limited clinical data evaluating the impact of baseline patient characteristics on response to hypofractionated treatment. This study sought to evaluate how patient age and prostate size affects voiding symptoms, irritative symptoms, and sexual function, following stereotactic body radiotherapy (SBRT). Methods: This retrospective analysis includes 102 non-metastatic patients treated with SBRT at a single institution between May 2008 and September 2014. The course of radiotherapy consisted of 36.25 Gy (range 35–40) over 5 daily fractions. International Prostate Symptom Score (IPSS) and Sexual Health Inventory for Men (SHIM) were recorded at baseline, 1, 3, 6, 9, 12, 18, 24, and 36 months after treatment. Results: Median patient age was 68 years old (range 47-88) and median prostate volume was 43 cc (range 18.7-170.7). Baseline IPSS irritative score, IPSS voiding score, and SHIM score were 5.34, 5.42, and 13.55. A statistically significant increase in voiding (7.02), irritative (7.21), and decrease in SHIM score (11.77) was observed after one month (p < .05). The IPSS irritative score and IPSS voiding scores returned to baseline in >90% of patients by 9 months and SHIM scores returned to baseline in >90% of patients by 2 years. Prostate size ≤ 50 cc showed higher baseline IPSS voiding and irritative resolution rates after 3 months (p < .05). Conclusions: While an increase in IPSS irritative score, and a decrease in SHIM score initially occurred, all symptoms return to baseline within three years. Age did not affect urinary or sexual dysfunction following radiotherapy. Patients with smaller prostate volumes had significantly better voiding and irritative outcomes when compared to larger volumes.