This record contains raw data related to the article "Stereotactic radioablation for the treatment of ventricular tachycardia: preliminary data and insights from the STRA-MI-VT phase Ib/II study" Abstract Purpose We present the preliminary results of the STRA-MI-VT Study (NCT04066517), a spontaneous, phase Ib/II study, designed to prospectively test the safety and efficacy of stereotactic body radiotherapy (SBRT) in patients (pts) with advanced cardiac disease and intractable ventricular tachycardia (VT). Methods Cardiac computed tomography (CT) integrated by electroanatomical mapping was used for substrate identification and merged with dedicated CT scans for treatment plan preparation. A single 25-Gy radioablation dose was delivered by a LINAC-based volumetric modulated arc therapy technique in a non-invasive matter. The primary safety endpoint was treatment-related adverse effects during acute and long-term follow-up (FU), obtained by regular in-hospital controls and implantable cardioverter defibrillator (ICD) remote monitoring. The primary efficacy endpoint was the reduction at 3 and 6 months of VT episodes and ICD shocks. Results Seven out of eight patients (men; age, 70 ± 7 years; ejection fraction, 27 ± 11%; 3 ischemic, 4 non-ischemic cardiomyopathies) underwent SBRT. At a median 8-month FU, no treatment-related serious adverse event occurred. Three patients died from non-SBRT-related causes. Four patients completed the 6-month FU: the number of VT decreased from 29 ± 33 to 11 ± 9 (p = .05) and 2 ± 2 (p = .08), at 3 and 6 months, respectively; shocks decreased from 11 to 0 and 2, respectively. At 6 months, all pts. showed a significant reduction of VT episodes and no electrical storm recurrence, with the complete regression of iterative VTs in 2/2 pts. Conclusion The STRA-MI-VT Study suggests that SBRT can be considered an alternative option for the treatment of VT in patients with structural heart disease and highlights the need for further clinical investigation addressing safety and efficacy. Keywords Ventricular tachycardia/ventricular arrhythmias · Stereotactic body radiotherapy/radioablation · Catheter ablation · Structural heart disease/dilated cardiomyopathy · Multimodal imaging

This study was supported by the Italian Ministry of Health with 5 × 1000 funds and Ricerca Corrente (RC 2019 – EF 5A—ID 2754331 to Centro Cardiologico Monzino, IRCCS). This study was supported by a research grant from the Fondazione IEO-CCM entitled "STereotactic RadioAblation by Multimodal Imaging for Ventricular Tachicardia (STRA-MI-VT)." The sponsors did not play any role in the study design, collection, analysis, and interpretation of data, nor in the writing of the manuscript, nor in the decision to submit the manuscript for publication.