Stereotactic Ablative Radiotherapy (SAbR) for Treatment of Ventricular Tachycardia (VT) Refractory Standard Invasive Ablation Techniques


The purpose of this study is to evaluate the clinical efficacy and safety of stereotactic ablative radiotherapy (SAbR), also known as stereotactic body radiation therapy (SBRT), for treatment of ventricular tachycardia (VT) requiring implantable cardioverter defibrillator (ICD) treatments in patients with VT refractory to standard invasive ablation techniques. We hypothesized that SAbR is effective in suppressing sustained VT and reducing ICD treatments in this group of patients and is associated with acceptably low risk of serious complications.

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: N/A
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Treatment
    • Masking: None (Open Label)
  • Study Primary Completion Date: March 1, 2022


  • Radiation: Stereotactic ablative radiotherapy
    • Stereotactic ablative radiotherapy (SAbR) delivers of a potent, ablative or nearly ablative dose of radiation in oligofractions (ie, five or fewer fractions) primarily to create a compact dose delivered accurately to the intended target with steep gradients in all directions (geometric avoidance) and avoid damaging normal tissues.

Arms, Groups and Cohorts

  • Other: Arm
    • No arm

Clinical Trial Outcome Measures

Primary Measures

  • Primary efficacy outcome of ICD (implantable cardioverter-defibrillator) Treatment
    • Time Frame: 6 months
    • Number of episodes of ICD (implantable cardioverter-defibrillator) treatment (including both ATP and shock) per month; comparing 6 months before and after SAbR (excluding the first 2-week blanking period post SAbR).

Participating in This Clinical Trial

Inclusion Criteria

  • Age ≥ 18 years
  • Have an ICD implanted > 6 months and all VT episodes in the past 6 months are available in device memory.
  • Within the past 3 months, the patient has at least one episode of symptomatic monomorphic VT that requires ICD treatment (anti-tachycardia pacing and/or ICD shock) or was sustained/incessant but falls under ICD treatment zone. These VT episodes must occur after at least one standard invasive VT ablation or occur in a patient that is clinically deemed not eligible to the standard VT ablation procedure.
  • Two independent cardiac electrophysiologists reviewed the case and agreed that the patient would benefit from suppression of these VT episodes but there is no optimal invasive VT ablation or antiarrhythmic drug options.

Exclusion Criteria

  • Has contraindication to receive SAbR or VT clinically deemed not suitable for SAbR.
  • Is pregnant
  • Has severe co-morbid medical condition or terminal illness and is unlikely to survive more than 6 months regardless of VT status based on clinical judgement by treating or enrolling physicians.
  • On potent immunosuppressive therapy (e.g., post organ transplant)
  • Has severe collagen vascular disorder with organ involvement
  • Not willing or not able to consent to participate in the study

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • University of Texas Southwestern Medical Center
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • james Daniel, MD, Principal Investigator, UT Southwestern Medical Center
  • Overall Contact(s)
    • james Daniel, MD, 2146458000,

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