A Review of Cardiac Radioablation (CR) for Arrhythmias: Procedures, Technology, and Future Opportunities

Purpose: Cardiac radioablation (CR), a new treatment for cardiac arrhythmias such as ventricular tachycardia and atrial fibrillation, has had promising clinical outcomes to date. There is consequent desire for rapid clinical adoption. However, CR presents unique challenges to radiation therapy, and it is paramount that clinical adoption be performed safely and effectively. Recent reviews comprehensively detail patient selection, clinical history, treatment outcomes, and treatment toxicities but only briefly mention the technical aspects of CR. To address this knowledge gap, this review collates currently available knowledge regarding CR technology choice and procedural details to help inform and guide clinics considering implementing their own CR program, to aid technique standardization, and to highlight areas that require further development or verification. Methods and Materials: Original preclinical and clinical scientific articles that sufficiently detailed CR technical aspects, including pretreatment electrophysiology and imaging, motion analysis and management techniques, treatment planning, and/or treatment delivery, were identified within a comprehensive literature search. Results: Nineteen preclinical and 18 clinical scientific articles sufficiently detailed the technical aspects of CR treatment deliveries on live subjects. The technical aspects of these scientific articles were diverse: Preclinical treatments have been performed with brachytherapy, photons, protons, and carbon ions, and clinical treatments have been performed with photons using conventional, robotic, and magnetic resonance imaging guided systems. Other technical aspects demonstrated similar variability. Conclusions: This review summarizes the technical aspects and procedural details of preclinical and clinical CR treatment deliveries and highlights the complexity and current variability of CR. There is need for standardized procedural reporting