Trial in Arrhythmia Radioablation for Ventricular Tachycardia: Single Fraction vs Three Fractions

Ventricular tachycardia (VT) is a life-threatening heart rhythm disorder that arises from areas of diseased tissue in the heart. Treatment of VT can involve anti-arrhythmic drugs and catheter-based ablations. Unfortunately, despite multiple antiarrhythmic drugs, as well as the catheter-based ablation procedures, VT continues to persist in your case. At this point in time, The investigators believe that stereotactic body radiotherapy (SBRT) remains the only possible option to potentially treat VT. The investigators hypothesize that by administering SBRT at different dose levels and fractionation may achieve a better therapeutic ratio, defined as comparable efficacy with less risk of toxicity due to lower dose exposure to the normal tissue, including the heart vasculature, in patients when compared to VT patients who receive a dose of 25Gy in a single fraction which is the current treatment option.

This is a randomized dose de-escalation trial where the patients will be randomized in in one of the two experimental arms, receiving 1 single fraction OR 3 daily consecutive fractions of RT, and will be treated into a prespecified dose level group, based on the study development. The study includes three de-escalated consecutive dose level groups for each of two randomized treatment arms and there will be 3 patients per group and each group will receive a particular radiation treatment either as single treatments or three treatments.

The purpose of this treatment is to safely reduce episodes of VT.

Inclusion criteria

• Age ≥ 18 years
• Structural heart disease:

• Ischemic cardiomyopathy
• Non-ischemic cardiomyopathy
• Hypertrophic cardiomyopathy
• Refractory VT severity:

• VT leading to ICD shock with minimum 3 episodes in any 3-month period without reversible cause;
• Failed or intolerant to antiarrhythmic drug therapy (either amiodarone or ≥ 2 AADs) AND failed ablation (CA)
• OR ablation (CA) contraindicated
• Ability to understand study protocol and to write informed consent
• Willing to comply with specified pre-, post- and follow-up testing, evaluations and requirements
• Expected to remain available for at least 36 months after enrollment

Exclusion criteria

• Age < 18 years
• Pregnancy
• Prior chest radiation therapy