1 Klinika onkologická, FN Ostrava, Ostrava
Abstract
Authors present precodural aspects based on case report series of cardiac radiosurgery in a patient with malignant ventricular tachycardia.
Material and methods
Patients with stable chronic heart failure (NYHA II, III) with decreased left ventricular ejection fraction, recurrent therapies for VT from Implantable Cardioverter Defibrillator (ICD) and failure of catheter ablation were treated by radiosurgical ablation. Stereotactic radiosurgery system CyberKnife was used. The location of the critical part of the arrhythmogenic substrate was determined by electroanatomic mapping during catheter ablation procedure. The ICD lead was used as a surrogate for compensation of respiratory movements. No additional margin for Planning Target Volume (PTV) was added.
Results
From January 2014 until March 2017, ten patients (9 males/1 female), mean age 66 years (range 64-80) received radiosurgical ablation 25Gy in one fraction. Mean PTV, treatment duration, isodose line with prescribed dose, conformality index, and homogeneity index were 22.15 ccm (range 14.2-29.6), 68 min (range 45-80), 80% (range 66-84), 1.28 (range 1.15-1.78) and 1.24 (range 1.19-1.52), respectively. Nine correlation models have to be often created, median one per 12 minutes (range 2-15 min), to reach precision better than 3 mm (average correlation error 1,1 mm).
Conclusion
Stereotactic radiosurgery of recurrent ventricular tachycardia is feasible and seems a viable option as a bail-out procedure after failed catheter ablation of VT.
