# Cardiac Stereotactic Body Radiation Therapy (SBRT) for Refractory Ventricular Tachycardia Using Innovative Motion Tracking With Electroanatomical Mapping and CyberKnife Synchrony

## TL;DR

This paper describes a new method using radiation therapy to treat hard-to-manage heart rhythm disorders by combining motion tracking and 3D heart imaging.

## Contribution

A novel cardiac SBRT approach integrating real-time motion tracking and 3D heart reconstruction for refractory VT.

## Key findings

- A 66-year-old patient with refractory VT was successfully treated with a single SBRT session using motion tracking.
- Six months post-treatment, the patient remained free from VT without needing further interventions.
- The method was successfully implemented using inHeart and Synchrony technologies.

## Abstract

Ventricular tachycardia (VT) is a potentially fatal arrhythmia that often requires a combination of medications and invasive procedures, including implantable cardioverter defibrillators (ICDs) and radiofrequency catheter ablation, to manage and treat. Despite these interventions, recurrence rates for VT remain high, particularly in patients with structural heart disease. Recent advancements in cardiac stereotactic body radiation therapy (SBRT) offer a promising alternative for patients with refractory VT, particularly for those whose arrhythmogenic areas are difficult to access through conventional methods. This study presents a novel approach to treating refractory VT, integrating advanced cardiorespiratory motion tracking using CyberKnife Synchrony (Accuray Incorporated, Madison, WI, USA) and a 3D heart reconstruction technology (inHeart, Pessac, France). The case involves a 66-year-old male with a history of dilated cardiomyopathy and recurrent VT, unresponsive to multiple medical and invasive interventions, including ICD implantation and catheter ablation. Using a combination of CT imaging, MRI, and electroanatomical mapping, we identified the arrhythmogenic region of the heart. He then underwent a single fraction of SBRT, 25 Gy to the target area, using real-time motion tracking via Synchrony. Six months post-treatment, the patient remained free from VT and has not required ICD therapies or further medical or procedural interventions. Our center has successfully implemented cardiac SBRT for refractory VT using inHeart technology for heart reconstruction and Synchrony for cardiorespiratory motion tracking.