Question special

Phil et al. congratulations on leading this important effort and pioneering a novel therapy for VT patients! I have 3 questions related to the observed treatment effect with stereotactic radiotherapy:

1. Patients underwent multiple prior ablation procedures and had frequent episodes of recurrent VT. Do the authors think that these episodes new VTs emerging from previously unablated areas or resulting from insufficient/ineffective ablation?
2. In most patients multiple prior catheter-based VT ablations were performed and it seems that they presented clinically with only 1-2 monomorphic VT morphologies. Is it possible that similar benefit would have been observed with a repeat catheter ablation targeting the remaining VT morphologies and that the observed results may reflect a cumulative beneficial effect of catheter ablation + radiotherapy?