Stereotactic Body Radiotherapy for Refractory Ventricular Tachycardia: From Serendipity to Precision Biological...

Ventricular arrhythmias (VAs), particularly refractory ventricular tachycardia (VT), pose a significant therapeutic challenge and are associated with high morbidity and mortality. For patients who do not respond to conventional therapies, including antiarrhythmic drugs and catheter ablation (CA), stereotactic body radiotherapy (SBRT)-also known as stereotactic arrhythmia radioablation (STAR)-has emerged as a promising non-invasive alternative. This review synthesizes current clinical evidence from prospective trials, retrospective series, and case reports that collectively demonstrate the efficacy of STAR in reducing VT burden and improving quality of life. This review also explores the evolving understanding of the associated underlying biological mechanisms, which appear to involve a complex interplay between early electrophysiological conduction reprogramming and delayed structural myocardial remodeling mediated by inflammation and fibrosis. Finally, we address the critical technical considerations, including patient selection, target delineation using multimodal imaging and electroanatomic mapping, motion management, and treatment planning, which are essential for the safe and effective delivery of STAR. While short-term outcomes are encouraging, ongoing research is needed to optimize dosing, refine techniques, and establish long-term efficacy and safety.