Question special

Congratulations for this outstanding work which makes us entering into a new era of therapy.
I have a question about your target. You chose the 10 msec before QRS onset on ECGi if I am correct? Why this target?
Isthmus is definitely extremely complicated to identify with ECGi because isthmus EGMs (sometimes measured as low as 0.04mV with contact mapping) are hidden into unipolar EGM due to the surrounding tissue but why not targeting the substrate? Since the VISTA study, targeting the substarte seems more effective than just targeting the clinical VT.
Don't you think that wall thinning on CT scan or DE on MRI may improve scar localisation and better identification of the target?
Do you think the scar would be too large to be a target and would require too much radiation to be eliminated?
Thanks again for this fascinating work.