B-AB04-01 STEREOTACTIC BODY RADIOTHERAPY FOR REFRACTORY SCAR RELATED VENTRICULAR TACHYCARDIA: A SINGLE CENTER EXPERIENCE

Abstract

Stereotactic body radiation therapy (SBRT) is an emerging treatment option for ventricular tachycardia (VT) refractory to catheter ablation (CA). To describe experience with SBRT for refractory VT with acute and mid-term outcomes. This is a single-center experience of patients who underwent SBRT for VT. The target for therapy was defined based on all available data including 12-lead ECG VT morphology, cardiac imaging, and electroanatomic mapping data. 25 Gy was delivered with 4D CT planning and conebeam CT guidance. All patients were placed on anticoagulation post and had follow up echocardiography and chest CT. A 4-week blanking period was used for VT outcomes. Ten patients with significant scar on cardiac imaging or electroanatomic mapping underwent SBRT; 6 (60%) for VT refractory to treatment, 2 with contraindication to CA, and 2 patients with inaccessible epicardial substrate. 8 (80%) had VT storm. Patients were 62.6±7.8 years, with mean LVEF of 33±14%. All failed antiarrhythmic therapy and amiodarone in 9 (90%) and had 2.2±0.9 prior CA. 9 (90%) had one or more CA at our institution. During a median follow-up of 6.5 months, VT episodes decreased from 44 ± 108 6 months prior to therapy to 4 ± 7 (p = 0.02). ICD shocks decreased from 4.8 ± 3.4 to 0 (p=0.002). 3 (30%) of patients had VT in the first 3 weeks post treatment with no VT after. Two patient deaths occurred in the follow-up period that were unlikely related to SBRT. No short-term complications or changes on ECHO were noted. In patients with VT refractory to medications and CA, SBRT was associated with a marked reduction in VT burden and ICD shocks. Long term outcomes and complications are unknown.