Phase I/II Trial of Electrophysiology-Guided Noninvasive Cardiac Radioablation for Ventricular Tachycardia

Circulation. 2019 Jan 15;139(3):313-321. doi: 10.1161/CIRCULATIONAHA.118.038261.


Background: Case studies have suggested the efficacy of catheter-free, electrophysiology-guided noninvasive cardiac radioablation for ventricular tachycardia (VT) using stereotactic body radiation therapy, although prospective data are lacking.

Methods: We conducted a prospective phase I/II trial of noninvasive cardiac radioablation in adults with treatment-refractory episodes of VT or cardiomyopathy related to premature ventricular contractions (PVCs). Arrhythmogenic scar regions were targeted by combining noninvasive anatomic and electric cardiac imaging with a standard stereotactic body radiation therapy workflow followed by delivery of a single fraction of 25 Gy to the target. The primary safety end point was treatment-related serious adverse events in the first 90 days. The primary efficacy end point was any reduction in VT episodes (tracked by indwelling implantable cardioverter defibrillators) or any reduction in PVC burden (as measured by a 24-hour Holter monitor) comparing the 6 months before and after treatment (with a 6-week blanking window after treatment). Health-related quality of life was assessed using the Short Form-36 questionnaire.

Results: Nineteen patients were enrolled (17 for VT, 2 for PVC cardiomyopathy). Median noninvasive ablation time was 15.3 minutes (range, 5.4-32.3). In the first 90 days, 2/19 patients (10.5%) developed a treatment-related serious adverse event. The median number of VT episodes was reduced from 119 (range, 4-292) to 3 (range, 0-31; P<0.001). Reduction was observed for both implantable cardioverter defibrillator shocks and antitachycardia pacing. VT episodes or PVC burden were reduced in 17/18 evaluable patients (94%). The frequency of VT episodes or PVC burden was reduced by 75% in 89% of patients. Overall survival was 89% at 6 months and 72% at 12 months. Use of dual antiarrhythmic medications decreased from 59% to 12% ( P=0.008). Quality of life improved in 5 of 9 Short Form-36 domains at 6 months.

Conclusions: Noninvasive electrophysiology-guided cardiac radioablation is associated with markedly reduced ventricular arrhythmia burden with modest short-term risks, reduction in antiarrhythmic drug use, and improvement in quality of life.

Clinical trial registration: URL: . Unique identifier: NCT02919618.

Keywords: noninvasive; stereotactic radiotherapy; ventricular tachycardia.

Publication types

  • Clinical Trial, Phase I
  • Clinical Trial, Phase II
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials*
  • Aged
  • Aged, 80 and over
  • Anti-Arrhythmia Agents / therapeutic use
  • Electrophysiologic Techniques, Cardiac*
  • Female
  • Heart Ventricles / physiopathology
  • Heart Ventricles / radiation effects*
  • Humans
  • Male
  • Middle Aged
  • Missouri
  • Predictive Value of Tests
  • Prospective Studies
  • Quality of Life
  • Radiofrequency Ablation / adverse effects
  • Radiofrequency Ablation / methods*
  • Radiosurgery / adverse effects
  • Radiosurgery / methods*
  • Recurrence
  • Risk Factors
  • Surveys and Questionnaires
  • Tachycardia, Ventricular / diagnosis
  • Tachycardia, Ventricular / physiopathology
  • Tachycardia, Ventricular / radiotherapy*
  • Time Factors
  • Treatment Outcome
  • Ventricular Premature Complexes / diagnosis
  • Ventricular Premature Complexes / physiopathology
  • Ventricular Premature Complexes / radiotherapy*


  • Anti-Arrhythmia Agents

Associated data