Clinical Experience of Stereotactic Body Radiation For Refractory Ventricular Tachycardia in Advanced Heart Failure Patients

Abstract Background Stereotactic body radiation therapy (SBRT) has been shown to be effective in treating patients with refractory ventricular tachycardia. Objective We sought to describe outcomes for SBRT in advanced heart failure patients admitted for repeated ICD therapies who were refractory to standard treatments. Methods SBRT simulation, planning and treatments were performed using standard techniques with collaboration from a radiation oncologist, electrophysiologist and cardiac imaging specialist. Patients were treated with a single fraction 25 Gy while awake. Efficacy was assessed by total durations in seconds of ventricular tachycardia, frequency of anti-tachycardia pacing (ATP), and the quantity of shocks before and after treatment as recorded by implantable cardioverter-defibrillators (ICDs). Results A total of 10 patients (mean age 61, 3 female) were included. Etiologies of heart failure were ischemic in 40% (4/10) and nonischemic in 60% (6/10). Among 8 patients with available ICD data, the total reduction in seconds of detected VT was 69% (pre-treatment 1065 seconds/month vs. post-treatment 332 seconds/month). The total reduction in ATP sequences was 48% (17.3 pre-treatment and 8.9 post-treatment). Reduction in total ICD shocks after SBRT was 68% (2.9 shocks/month pre-treatment and 0.9 shocks/month post treatment). When excluding a single non-responder, there was a significant reduction in VT seconds (94%, p=0.04) and a trend towards ICD shock reduction (90%, p=0.07) post SBRT. Conclusions Noninvasive treatment with SBRT was feasible and modestly effective at reducing VT burden in the critically ill. This suggests that SBRT treatment may be a useful palliation for electrical storm.