Extended follow-up of stereotactic body radiation therapy for refractory ventricular arrhythmias

INTRODUCTION: Stereotactic body radiation therapy (SBRT) is an increasingly utilized non-invasive treatment for patients with ventricular arrhythmias refractory to conventional treatments. There are limited data on long term outcomes. METHODS: Patients with ventricular arrhythmias refractory to traditional treatments underwent SBRT after a multidisciplinary discussion. Patients were followed clinically, and ventricular arrhythmia burden and ICD therapies were quantified. RESULTS: There were 26 patients who underwent a total of 28 SBRT sessions. Patients were followed for a median of 221 days (IQR 67, 608). Ventricular arrhythmia burden was reduced comparing a median 20 (IQR 15, 31) episodes in the 6 months pre-SBRT compared to a median 3 episodes (0,26) in the 6 months post-SBRT (p < 0.001), excluding a 6-week blanking period. Patient mortality was 58% over follow-up and ventricular arrhythmia recurrence was 81% in those patients who survived outside of the blanking period. There were no complications related to SBRT reported. CONCLUSIONS: In this series of patients with severe cardiomyopathy who weren’t candidates for traditional therapies and underwent palliative SBRT for ventricular arrhythmias, arrhythmia recurrence is common; however, arrhythmia burden is reduced following SBRT. Until randomized trial evidence is available, these data support SBRT as a bailout treatment option.