Dose Escalation for SBRT of Recurrent VT Ventricular Tachyarrhythmia - a Single Center, Phase II Clinical Trial (DEFT STAR)

Dose Escalation for Stereotactic Cardiac Radiation Therapy of Recurrent Ventricular Tachyarrhythmia - a Multi Center, Phase II Clinical Trial

The objective of this study is to demonstrate that higher radiation doses are necessary to induce transmural scar formation which is currently assumed to be the underlying mechanism of successful long-term efficacy of VT treatment and therefore dose-escalation will lead to a significantly reduced long-term VT recurrence rate compared to the currently applied single dose of 25 Gy.

Study Overview

• Status: Recruiting
• Conditions: Ventricular Tachycardia
• Intervention / Treatment: Device: Dose escalating stereotactic arrhythmia radioablation to treat ventricular tachycardia (VT)

• Study Type: Interventional
• Enrollment (Estimated): 15
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Nicolaus Andratschke, MD; Phone Number: 0041 44 255 4238; Email: nicolaus.andratschke@usz.ch
• Study Contact Backup: Name: Michael Mayinger, MD; Phone Number: 0041 44 255 4238; Email: michael.mayinger@usz.ch

Study Locations

• Czech Republic
  • Ostrava, Czech Republic
    • Recruiting
    • University Hospital Ostrava
    • Contact: Jakub Cvek, Prof.; Phone Number: +420 597 372 142; Email: jakub.cvek@fno.cz
• Switzerland
  • Zurich
    • Zürich, Zurich, Switzerland, 8091
      • Recruiting
      • University Hospital Zurich
      • Contact: Michael Mayinger, MD; Phone Number: 0041432530691; Email: michael.mayinger@usz.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Patients with structural heart disease, in particular ischemic and non-ischemic cardiomyopathy: Implanted ICD and/or CRT-D. Prior ≥1 failed catheter ablation (with endocardial ± epicardial approach based on the substrate location and the ECG morphology of clinical VTs) procedure to control sustained monomorphic VT using currently recommended mapping and ablation techniques,2 or patients in whom ablation is not feasible. Reasons for lack of epicardial ablation and non-feasibility of catheter ablation must be specified. Sustained VT recurrence after catheter ablation on optimised antiarrhythmic medication.

Age ≥18 years. IRB-approved, written informed consent must be provided

Exclusion Criteria:

Patients with only premature ventricular contractions.

Patients with sustained VT/VF who demonstrate:

Acute myocardial infarction; Primary electrical disease (channelopathy); Reversible and treatable cause (e.g., drug-induced or intoxication) of VT that can be adequately addressed otherwise; A target that cannot be safely and precisely defined based on stereotactic radiotherapy accuracy requirements (e.g., anatomical interference from OARs, overlapping prior radiation therapy to the thoracic region); Pregnancy or breastfeeding; Inability to provide informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Dose escalating stereotactic arrhythmia radioablation to treat ventricular tachycardia (VT)

Device: Dose escalating stereotactic arrhythmia radioablation to treat ventricular tachycardia (VT); Dose escalating stereotactic arrhythmia radioablation to treat ventricular tachycardia (VT) refractory to conventional antiarrhythmic and catheter ablation-based therapy. First patients will be treated with a dose from 25 Gy prescribed to the 65-90% target volume encompassing isodose escalating to a maximum of 32.5 Gy prescribed to the 65-90% isodose.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
safety measured by registered radiation associated adverse events up to 90 days	safety measured by registered radiation associated adverse events	up to 90 days

Secondary Outcome Measures

Outcome Measure	Time Frame
Radiation associated serious adverse event (at least grade 4 or 5 according to CTCAE v5)	As assessed at 90 days

Collaborators and Investigators

• Sponsor: University of Zurich

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2022
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: October 21, 2022
• First Submitted That Met QC Criteria: October 21, 2022
• First Posted (Actual): October 26, 2022

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 26, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiac Conduction System Disease; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Tachycardia; Tachycardia, Ventricular
• Other Study ID Numbers: 2022-00262

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No