Feasibility Study on Cardiac Arrhythmia Ablation Using High-Energy Heavy Ion Beams


Feasibility Study on Cardiac Arrhythmia Ablation Using High-Energy Heavy Ion Beams

Lehmann, I. H.; Graeff, C.; Simoniello, P.; Constantinescu, A.; Takami, M.; Lugenbiel, P.; Richter, D.; Eichhorn, A.; Prall, M.; Kaderka, R.; Fiedler, F.; Helmbrecht, S.; Fournier, C.; Erbeldinger, N.; Thomas, D.; Katus, H. A.; Johnson, S. B.; Parker, K. D.; Debus, J.; Asirvatham, S. J.; Bert, C.; Durante, M.; Packer, D. L.

Rationale ─ Accelerated carbon ions (12C) are rigorously accurate and effective in cancer radiation therapy.
Objective ─ To ablate cardiac locations using a scanned 12C beam in an intact chronic sham-controlled large animal model.
Methods and Results ─ Seventeen pigs were randomized to irradiation of atrioventricular junction (AVJ; 25, 40, and 55 Gy), left atrial right superior pulmonary vein junction (40 Gy), freewall LV (40 Gy), and sham-group. Electroanatomical (EA) mapping, fiducial-, and pacemaker implantation were performed. Cardiac gated CTs were obtained during breath-hold at expiration. Targets were contoured and case-specifically expanded for motion coverage. 12C was delivered using rescanned raster pencil-beams. Animals were followed for up to 6 months.
Fourteen pigs (mean weight 33.8 ± 3.5 kg) were irradiated using a horizontal beam line. For AVJ a mean volume of 1.8 ± 0.1 cc was irradiated. For PVI and LV, mean volumes were 14.9 ± 1.8, and 2.4 ± 0.3 cc, respectively. Risk structures were spared. Animals stayed in sinus rhythm during irradiation. In-beam positron-emission-tomography confirmed precise 12C delivery. Complete atrioventricular block developed over the course of 4 months in 40 and 55 Gy animals. EA mapping confirmed an area without electrogram in the His-location. Histology revealed strong target fibrosis. Apoptosis was found as one of the mechanisms of cell death, being present after 3, but not 6 months.
Conclusion ─ Accelerated 12C is a highly focused form of particle therapy that is a new means for precise cardiac arrhythmia elimination without any invasive procedural access to the body.

Keywords: Atrial Fibrillation; Particle Therapy; Carbon Ion Beam; Atrioventricular Node; Ventricular Tachycardia; Ablation; Catheter-free

Permalink: https://www.hzdr.de/publications/Publ-22674
Publ.-Id: 22674