Abstract
BACKGROUND: Evidence supporting the efficacy of stereotactic body radiotherapy (SBRT) for localized prostate cancer is accumulating, but comparative studies of patient-reported quality of life (QOL) following SBRT versus conventionally fractionated external beam radiotherapy (EBRT) or active surveillance (AS) are limited. OBJECTIVE: To compare QOL of patients pursuing SBRT and EBRT versus AS. DESIGN, SETTING, AND PARTICIPANTS: A population-based cohort of 680 men with newly diagnosed localized prostate cancer was prospectively enrolled from 2011 to 2013. INTERVENTION: SBRT, EBRT without androgen deprivation therapy, or AS. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: QOL was prospectively assessed before treatment (baseline), and at 3, 12, and 24mo after treatment using the validated Prostate Cancer Symptom Indices, which contain four domains: sexual dysfunction, urinary obstruction/irritation, urinary incontinence, and bowel problems. Propensity weighting via logistic regression models was used to balance baseline characteristics, and the mean QOL scores of EBRT and SBRT patients were compared against AS patients as the control group. RESULTS AND LIMITATIONS: Compared with AS patients, EBRT patients had worse urinary obstructive/irritative symptoms and sexual dysfunction at 3mo, and worse bowel symptoms at 3 and 24mo. SBRT patients had similar scores as AS patients in all domains and across all time points; however, due to small sample size, worse sexual function and urinary incontinence in SBRT patients cannot be ruled out. Further research is needed to assess long-term outcomes. CONCLUSIONS: In a nonrandomized cohort of men with localized prostate cancer, SBRT appeared to result in favorable QOL results through 2yr of follow-up, but worse sexual function and urinary incontinence compared with AS cannot be ruled out completely. Larger studies with longer follow-up are needed to confirm these findings. PATIENT SUMMARY: Stereotactic body radiotherapy (SBRT) and active surveillance appear to have similar quality of life outcomes through 2yr, although worse sexual function and urinary incontinence from SBRT cannot be ruled out completely.