BACKGROUND: Stereotactic arrhythmia radioablation (STAR) is a novel, noninvasive technique for the management of refractory ventricular tachycardia (VT). OBJECTIVE: This retrospective study aimed to assess the feasibility, efficacy, and safety of STAR in an Australian cohort. METHODS: From February 2020 to August 2023, 12 patients with drug-refractory VT for whom catheter ablation had failed or who were unsuitable for it were treated with STAR in 2 Australian centers. A combination of electrocardiograms, multimodality imaging, and noninvasive or invasive mapping data was used to target the presumed VT substrate. All treatments (25 Gy in 1 fraction) were delivered without anesthesia. Efficacy end points were defined as the number of VT episodes, antitachycardia pacing sequences, VT storms, and shocks 6 months before and after treatment (6-week blanking period). Mortality and adverse event data were collected during 12-month follow-up. RESULTS: In the 9 patients who survived the blanking period, a significant reduction (64.5%
P = .011) in VT burden and VT storm (71.7%
P = .027) was observed during a 6-month follow-up. However, 66.7% (6/9) of these patients experienced VT recurrence
3 of 6 patients with recurrence with electrocardiograms available for review had the same VT morphology as before STAR. During a 12-month follow-up, 5 patients died and 3 adverse events were recorded (undersensing of defibrillator lead, increased rate of reflux, and radiation pneumonitis). CONCLUSION: This paper summarizes the initial Australian experience treating refractory VT with STAR. It demonstrates that STAR can significantly decrease the VT and VT storm burden during a 6-month follow-up with an acceptable acute adverse effect profile, albeit with a high VT recurrence rate.