Dr. Alexander Pryanichnikov

M.Sc. Huoqin Zhou

Motivation
Stereotactic Arrhythmia Radioablation (STAR) is a promising non-invasive treatment for life-threatening Ventricular Tachycardia (VT), particularly in patients who do not respond to medication or catheter ablation. Current STAR treatments are photon-based, which limits dose conformity and biological effectiveness. Ion beams, such as protons, helium, and carbon ions, offer superior dose localization due to the Bragg peak and, in the case of helium and carbon, increased linear energy transfer, which may enhance the formation of therapeutic myocardial scar tissue.
However, cardiac radioablation presents major technical challenges. The arrhythmogenic substrate is only 1–2 mm thick and is affected by both respiratory and cardiac motion. In scanned proton or ion beam therapy, motion-induced interplay effects can compromise dose precision. This project investigates the feasibility of combining multi-ion irradiation with dual motion (respiratory and cardiac synchronization) using a dual-dynamic anthropomorphic phantom. The goal is to assess whether highly precise, motion-compensated ion beam STAR is technically achievable and to generate pilot data for future translational research.

Project Objectives
The main objective is to evaluate the technical feasibility of dual dynamic multi-ion STAR under realistic motion conditions. Specifically, the project aims to:
(1) conduct treatment panning study with proton, helium, and carbon ion beams; (2) perform pilot dosimetric measurements with proton, helium, and carbon ion beams; (3) compare dose delivery under static and free-breathing, and (4) benchmark dose characteristics across ion species. The results will provide quantitative insight into motion effects, interplay phenomena, and the potential advantages of multi-ion therapy for cardiac radioablation.

Methodology
The study will use a dual-dynamic deformable anthropomorphic thoracic phantom with integrated respiratory and cardiac motion systems. Irradiations will be performed in pencil-beam scanning mode. During the first stage in-silico treatment panning study will be conducted. The experimental workflow includes static measurements, free-breathing motion experiments, and phase-controlled step-and-shoot irradiation. Dose measurements will be performed using an ionization chamber and electrometer system. The collected data will be analyzed to quantify motion-induced dose deviations and to compare performance across different ion species.