Stereotactic Management of Arrhythmia- Radiosurgery in Treatment of Ventricular Tachycardia (SMART-VT). Results of a Prospective Safety Trial

Background and purpose: Despite its increasing popularity, there are limited prospective data on stereo-tactic arrhythmia radioablation (STAR). In this trial, we assessed the safety and efficacy of STAR in patients with ventricular tachycardia (VT), focusing on early treatment-related grade >= 3 adverse events (AE).Materials and methods: This prospective trial was designed for adults with VT recurrence following cathe-ter ablation (CA) despite adequate pharmacotherapy, or contraindications to CA. A single dose of 25 Gy was delivered to the arrhythmia substrate defined on electro-anatomic mapping and cardiac-gated CT. The primary endpoint was safety, defined as two or fewer treatment-related grade >= 3 AEs during the first three months in 11 patients. Additional endpoints included treatment efficacy, clinical and biological markers of cardiac injury, and quality of life.Results: Eleven patients with a median age of 67 years, structural heart disease, and a clinically significant recurrence of VT despite adequate pharmacotherapy and 1-4 previous CAs were enrolled between 2020/09 and 2022/10. Following the treatment, one patient developed a possibly treatment-related grade >= 3 AE, a grade 4 heart failure exacerbation at 87 days, which resolved after conservative treat-ment. There was a total 84.3% reduction in VT burden in 10 evaluable patients; however, VT recurrence was eventually observed in eight, and three patients required additional CAs. Three deaths due to unre-lated causes were recorded.Conclusions: STAR appears to be safe and efficient. It is a promising treatment for selected patients; how-ever, long-term outcomes remain to be evaluated, and controlled trials comparing STAR with standards of care are missing.(c) 2023 The Author(s). Published by Elsevier B.V. Radiotherapy and Oncology 188 (2023) 109857