One-year outcomes after stereotactic body radiotherapy for refractory ventricular tachycardia

Abstract:

Background

Cardiac stereotactic body radiotherapy (SBRT) has emerged as a promising noninvasive treatment for refractory ventricular tachycardia (VT).

Objective

Describe the safety and effectiveness of SBRT for VT in refractory to extensive ablation.

Methods

After maximal medical and ablation therapy patients were enrolled in a prospective registry. Available electrophysiologic and imaging data were integrated to generate a plan target volume (PTV) All SBRT was planned with a single 25 gray fraction utilizing respiratory motion mitigation strategies. Clinical outcomes at 6 weeks, 6 months and 12 months were analyzed and compared to the 6 months prior to treatment. The VT burden (ICD shocks and ATP sequences) as well as clinical and safety outcomes were the main outcomes.

Results

15 patients were enrolled and planned. 14 underwent treatment with 12 surviving to the end of the 6-week period and 10 surviving to 12 months. From 6 week to 12 months there was recurrence of VT which resulted in either appropriate ATP or ICD shocks in 33% (4/12). There were significant reductions in treated VT at 6 weeks to 6 months (98%) and 12 (99%) months compared to the 6 months prior to treatment. There was a nonsignificant trend towards lower amiodarone dose at 12 months. 4 deaths occurred after treatment with no changes in ventricular function.

Conclusion

For a select group of high-risk patients with VT refractory to standard therapy, SBRT is associated with a reduction of in VT and appropriate ICD therapies over 1 year.