Stereotactic Body Radiation Therapy for Ventricular Arrhythmias: Efficacy, Safety and Image Analysis-First Asian Population Study

Stereotactic body radiation therapy (SBRT) has been proved to be effective in refractory ventricular arrhythmia (VA). We report the first Asian series of SBRT for refractory VA in a group of Taiwanese. This study included patients with treatment-failure VA. 3D electroanatomic maps, delayed enhancement magnetic resonance imaging (DE-MRI) and dual energy computed tomography (CT) were used to identify scar substrates. The target volume was treated with a single radiation dose of 20 Gy delivered by Varian TrueBeam System. Efficacy was assessed by VA events recorded by implantable cardioverter defibrillator (ICD) or 24-hour Holter. Pre- and post-radiation therapy image studies were also performed. Adverse events were monitored during follow-up. From February 2019 to December 2019, 7 patients were enrolled. Six male and one female patients, mean age 55 years, received the treatment. Among the 7 patients with variety of cardiomyopathy, one patient died of hepatic failure. For the other 6 patients, at a median follow-up of 14.5 months, the burden of VA decreased significantly. Increased intensity of DE-MRI might be associated with lower risk of VA recurrence while the dual energy CT had lower sensitivity in the detection. No acute and minimal late adverse events were reported. We conclude that, in patients with refractory VA, SBRT was associated with a marked reduction in the burden of VA and DE-MRI might be useful to monitor treatment effect.