Outcome measures
pneumonitis, death, stroke, VT/VF, pericarditis, embolism, acute heart failure
PNEUMONITIS, CARDIAC TAMPONADE, ADVERSE EVENTS, STROKE, ICD MALFUNCTION, PERICARDITIS, ADVERSE EVENT, SECONDARY, ACUTE CORONARY SYNDROME, EMBOLISM, ACUTE HEART FAILURE
The primary outcome of this trial is safety measured by registered radiation associated adverse events (AE) up to 90 days after study intervention. This includes any radiation associated serious adverse event (SAE; at least grade 4 or 5 according to CTCAE v5), in particular death, radiation pneumonitis requiring hospitalization, radiation pericarditis requiring hospitalization and decrease in LVEF ≥ 10% as assessed by echocardiography or cardiac MRI. The secondary outcome measures include efficacy endpoints (i.e. freedom from sustained VT/VF), non-radiation associated safety and patient reported outcome measures (PROMS) as shown in Table 
Secondary outcome measures. QOL = quality of lifeNon-radiation associated safety, e.g.:Hospitalization for acute heart failure necessitating inotropic therapy and if needed mechanical circulatory support except when other reason is apparent (e.g. acute coronary syndrome)○ Cardiac tamponade○ Major stroke or systemic embolism according to current diagnostic standards○ ICD malfunction necessitating an interventional or operative approach