A Comparative Dosimetric Study of Proton and Photon Therapy in Stereotactic Arrhythmia Radioablation for Ventricular Tachycardia

Overview

Journal ArXiv

Date 2025 Feb 20

PMID 39975428

Authors

Keyur D Shah

Chih-Wei Chang

Pretesh Patel

Sibo Tian

Yuan Shao

Kristin A Higgins

Yinan Wang

Justin Roper

Jun Zhou

Zhen Tian

Xiaofeng Yang

Affiliations

Soon will be listed here.

Abstract

Purpose: Ventricular tachycardia (VT) is a life-threatening arrhythmia commonly treated with catheter ablation; however, some cases remain refractory to conventional treatment. Stereotactic arrhythmia radioablation (STAR) has emerged as a non-invasive option for such patients. While photon-based STAR has shown efficacy, proton therapy offers potential advantages due to its superior dose conformity and sparing of critical organs at risk (OARs), including the heart itself. This study aims to investigate and compare the dosimetry between proton and photon therapy for VT, focusing on target coverage and OAR sparing.

Methods: We performed a retrospective study on a cohort of 34 VT patients who received photon STAR. Proton STAR plans were generated using robust optimization in RayStation to deliver the same prescription dose of 25 Gy in a single fraction while minimizing dose to OARs. Dosimetric metrics, including D, D, D, and D, were extracted for critical OARs (heart, lungs, esophagus) and ventricular arrhythmogenic substrates (VAS). Shapiro-Wilk tests were used to assess normality, followed by paired t-tests or Wilcoxon signed-rank tests for statistical comparisons between modalities, with Bonferroni correction applied for multiple comparisons.

Results: Proton and photon plans achieved comparable target coverage, with VAS D of 24.1 ± 1.2 Gy vs. 24.7 ± 1.0 Gy (p=0.294). Proton therapy significantly reduced OAR doses, including heart D (3.6 ± 1.5 Gy vs. 5.5 ± 2.0 Gy, p<0.001), lungs D (1.6 ± 1.5 Gy vs. 2.1 ± 1.4 Gy, p<0.001), and esophagus D (0.3 ± 0.6 Gy vs. 1.6 ± 1.3 Gy, p<0.001), while maintaining optimal target coverage.

Conclusion: Proton therapy for STAR demonstrates significant dosimetric advantages in sparing the heart and other critical OARs compared to photon therapy for VT, while maintaining equivalent target coverage. These findings highlight the potential of proton therapy to reduce treatment-related toxicity and improve outcomes for VT patients.

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