Table 1.

Clinical studies of stereotactic radioablation for treatment of ventricular tachyarrhythmia

Study	Cvek et al.45	Loo et al.44	Cuculich et al.25	Jumeau et al.31	Haskova et al.49	Robinson et al.27	Zeng et al.50	Neuwirth et al.30	Qian et al.48	Gianni et al.32	Qian et al.51
Arrythmia	Ventricular tachycardia	Ventricular tachycardia	Ventricular tachycardia	Ventricular tachycardia	Ventricular tachycardia Cardiac fibroma	Ventricular tachycardia	Ventricular tachycardia Cardiac lipoma	Ventricular tachycardia	Atrial fibrillation	Ventricular tachycardia	Ventricular tachycardia
Study size (type)	N = 1 (case report)	N = 1 (case report)	N = 5 (case series)	N = 1 (case report)	N = 1 (case report)	N = 19 (prospective)	N = 1 (case report)	N = 10 (case series)	N = 2 (case series)	N = 5 (prospective)	N = 1
Age, years	72	71	Mean, 62 (range, 60-83)	75	34	Mean, 66 (range, 49-81)	29	Mean, 66 (range, 61-78)	53 and 59	Mean, 62.6 (range, 45-76)	77
Sex	Female	Male	Male, 4; female, 2	Male	Male	Male, 17; female, 2	Male	Male, 9; female, 1	Male, 1; female, 1	Male, 5	Male
Type of cardiomyopathy	Nonischemic	Ischemic	Ischemic, 2; nonischemic, 3	Nonischemic	None	Ischemic; 11; nonischemic, 8	None	Ischemic, 8; nonischemic, 2	None	Ischemic, 4; nonischemic, 1	Ischemic
NYHA class	Not reported	Not reported	III, 1 IV, 4	Not reported	I	I, 1 II, 4 III, 10 IV, 4	I	II, 6 III, 4	I, 2	I, 1 II, 4	Not stated
LV function	LVEF 25%	LVEF 24%	LVEF 23 (range, 15%-37%)	LVEF 15%	Normal	LVEF 25 (range, 15%-58%)	Normal	LVEF 26.5% ± 3.2%	Normal	LVEF 34% (range, 20%-55%)	LVEF 15%
AADs	β-Blocker	Sotalol Mexiletine	≥ 3 AADs, 4 2 AADs, 1	Not reported	β-Blocker Amiodarone	β-Blocker, 18 > 1 AAD, 11	Amiodarone Mexiletine	β-Blocker, 9 Amiodarone, 2 No AAD, 1	β-Blocker, 2 Amiodarone, 1 Propafenone, 1	1 AAD, 2 2 AADs, 3	Amiodarone Quinidine Mexiletine
Number of previous ablations	Previous endocardial and epicardial RF ablations	None	2 Patients, 0 1 Patient, 4 1 Patient, 1 1 Patient, 2	Previous RF catheter ablation	Cryoablation	Median number of previous catheter ablations, 1 (range, 0-4)	3 Percutaneous ablations 1 Epicardial ablation	3 Patients, 1 4 Patients, 2 2 Patients, 3 1 Patient, 5	None	3 Patients, 1 2 Patients, 2	Precious RF catheter ablation
Treatment planning	ECG Previous EP study CARTO and CT No additional margin added to ITV to make PTV	ECG, PET, and echocardiogram; PTV delineated by radiation oncology	ECG ECGI∗ SPECT or CMR PTV delineated by radiation oncologist	ECG MRI, PET, and EP study ITV with no additional margin added	ECG Previous EP study	ECG ECGI∗ SPECT or CMR 5 mm added as safety margin to form PTV	ECG Previous EP study Internal fiduciary marker placed transvenously Cardiac CT MultiPlan† treatment	ECG CARTO ECG-gated CT No additional margin for PTV ICD lead for respiratory motion MultiPlan† treatment	Internal fiduciary marker placed transvenously Contrast-enhanced CT CyberHeart System with CardioPlan software‡	ECG CT scan Placement of transjugular temporary active fixation lead (fiduciary marker) CardioPlan‡/MultiPlan† treatment	ECG Previous EP study
Treatment volume, cc	Not reported	Not reported	49.4 (range, 17.3-81.0)	21	Not reported	PTV, 98.9 (range, 60.9-298.8)	71	PTV 22.2 (range, 14.2-29.6)	48.5/54.5	PTV 143 ± 50 (range, 80-184)	Not stated
Treatment target	Base of the lateral wall of the LV	Inferoseptal, inferior and inferolateral wall	Anterior basal, 2 Inferior, 1 LV outflow and septum, 1 Inferolateral, 1	Posterior to the anterior segment of the basal interventricular septum	Between septum and posterior medial papillary muscle	Anterior, 5 Lateral, 6 Inferior, 6 Septal, 3 Apex, 4 LV summit, 2 RV, 1	LV wall adjacent to the interventricular groove	Anterolateral, 2 Inferior, 5 Inferolateral, 1 Posterobasal, 2	Pulmonary vein	Anterior mid, 1 Anterior midapical, septal midapical, 2 Basal and mid inferior apical inferior, 1 Septal, basal mid, 1	Anteroseptal and apical scar Sparing of the basal anteroseptum to preserve ICD lead, conduction system and valvular function
Radiation dose	27.6 Gy	33 Gy	25 Gy	25 Gy	25 Gy	25 Gy	24 Gy × 3	25 Gy	25 Gy	32 Gy	25 Gy
Treatment time	114 Minutes	90 Minutes	14 (Range, 11-18 min) minutes	45 Minutes	Not reported	15.3 (range, 5.4-32.3) minutes	69 Minutes	69 (Range, 45-80) minutes	90 Minutes	82 ± 11 (Range, 66-92) minutes	Not stated
Equipment	CyberKnife† Respiratory gating: Synchrony Respiratory Tracking† Immobilization: BodyFix‖	CyberKnife† Respiratory gating: Synchrony Respiratory Tracking† Immobilization: BodyFix‖	TrueBeam§ Respiratory gating: 4-dimensional CT Immobilization: BodyFix‖, Alpha Cradle¶	CyberKnife† Respiratory gating: 4-dimensional CT Immobilization: BodyFix‖	CyberKnife†	TrueBeam§ Respiratory gating: 4-dimensional CT Immobilization: BodyFix‖, Alpha Cradle¶	CyberKnife†	CyberKnife† Respiratory gating: tracking of ICD lead, 4-dimensional CT Immobilization: not stated	CyberKnife† Respiratory gating: tracking of ICD lead Immobilization: not stated	CyberKnife† Respiratory gating: X-Sight Spine Tracking System†, Synchrony Respiratory Tracking† Immobilization: not stated	Not stated
Complications (immediate)	None	None	None	None	None	None	None	Acute nausea (n = 4)	None	None	None
Results	Reduction in PVCs from 10% of all beats to 3% at 10 days; no malignant arrhythmia at 120 days	Reduction in VT episodes from 562 episodes to 52 episodes at 2-9 months	Reduction in total VT episodes from 6577 episodes over 15 patient-months to 4 episodes over 46 patient-months (99.9%)	Two episodes of slow VT during the first week; free of ICD shocks since SBRT; no electrical storm 4 months post treatment	Post procedure runs of VT. VT gradually disappeared over 8 months	Reduction in median VT episodes from 119 (range, 4-292) over 6 months to 3 (range, 0-31) over 6 months after 6-week blanking period; improvement in quality of life at 6 months	Reduction in VT from 189 to 0. No VT at 4-month follow-up	Reduction in VT burden by 87.6% over 3 months; reduction of median number of episodes from 18 to 0.93 (P = 0.012); recurrent electrical storm in 3 patients	Recurrence of AF at 6 months (n = 1) No recurrence at 6 months (n = 1)	Clinical follow-up from 10-14 months. Four patients had marked reduction in VT burden for first 6 months. All patients experienced clinically significant mid- to late-term VT	Arrhythmia-free at 4 months. Recurrence of VT upon discontinuation of antiarrhythmic medications requiring catheter ablation
Safety	No complications noted at 6 weeks; no pericardial effusion or radiation pneumonitis	No echo changes at 1,3, and 6 months	No changes in LV function; low-grade radiation pneumonitis resolved at 12 months; no effects on ICD system	No reported complications; improvement in LV function	No reported complications	No acute toxicity observed with ICDs during or after SBRT. 1 Heart failure exacerbation at 65 days 1 Pericarditis 5 Pericardial effusions 2 Grade II radiation pneumonitis 1 Gastropericardial fistula	No clinical or radiographic evidence	Acute toxicity of nausea (n = 4) 1 Patient with progression of mitral regurgitation (possible radiation-related toxicity) No change in LV function, NT-proBNP, or troponin No effects on ICD system	No reported adverse events Normal LV function on follow-up echo at 1 year	No clinical or imaging evidence of radiation necrosis or complications at 18 months Transient LV function reduction (n = 2)	Recurrence of VT
Mortality	Outcome reported only to 6 weeks; alive at 6 weeks	Deceased at 9 months from a COPD exacerbation	Fatal CVA 3 months after treatment in 1 patient with AF not receiving anticoagulants	Alive at 4 months	Alive at 8 months	Cardiac: n = 3 •Heart failure and recurrent VT (range, 5.5-15 months); pursued palliative care Noncardiac: n= 3 •Accidental asphyxiation •Amiodarone pulmonary toxicity •Biliary sepsis	Alive at 4 months	Cardiac: n = 2 •Heart failure (54 months) •Heart failure with refractory VT (18 months) Noncardiac:n = 1 •Vascular dementia and Alzheimer’s dementia at 43 months	Alive at 2 years	Cardiac: n = 2 •Heart failure (10 and 12 months)	Died at 8 months from refractory heart failure

AAD, antiarrhythmic drug; AF, atrial fibrillation; CARTO, Cartographic Information Division; CMR, cardiac magnetic resonance; COPD, chronic obstructive pulmonary disease; CT, computed tomography; CVA, cerebrovascular accident; ECG, electrocardiogram; ECGI, electrocardiographic imaging; echo, echocardiogram; EP, electrophysiology; ICD, implantable cardioverter defibrillator; ITV, internal target volume; LV, left ventricle; LVEF, left ventricular ejection fraction; MRI, magnetic resonance imaging; NT-proBNP, N-terminal pro b-type natriuretic peptide; NYHA, New York Heart Association; PET, positron emission tomography; PTV, planned target volume; PVC, premature ventricular contractions; RF, radio frequency; RV, right ventricle; SBRT, stereotactic body radiation therapy; SPECT, single-photon emission computed tomography; VT, ventricular tachycardia.

^∗ECGI from BioSemi BV (Amsterdam, The Netherlands).

^†MultiPlan software, CyberKnife, Synchrony Respiratory Tracking system, and X-Sight Spine Tracking System from Accuray Inc (Sunnyvale, CA).

^‡CyberHeart System and CardioPlan software from CyberHeart Inc (Sunnyvale, CA).

^§TrueBeam from Varian Medical Systems (Palo Alto, CA).

^‖BodyFix from Elekta (Stockholm, Sweden).

^¶Alpha Cradle from Smithers Medical Products, Inc (North Canton, OH).