Treatment of arrhythmias by external charged particle beams: a Langendorff feasibility study

Abstract

Hadron therapy has already proven to be successful in cancer therapy, and might be a noninvasive alternative for the ablation of cardiac arrhythmias in humans. We present a pilot experiment investigating acute effects of a 12C irradiation on the AV nodes of porcine hearts in a Langendorff setup. This setup was adapted to the requirements of charged particle therapy. Treatment plans were computed on calibrated CTs of the hearts. Irradiation was applied in units of 5 and 10 Gy over a period of about 3 h until a total dose of up to 160 Gy was reached. Repeated application of the same irradiation field helped to mitigate motion artifacts in the resulting dose distribution. After irradiation, PET scans were performed to verify accurate dose application. Acute AV blocks were identified. No other acute effects were observed. Hearts were kept in sinus rhythm for up to 6 h in the Langendorff setup. We demonstrated that 12C ions can be used to select a small target in the heart and, thereby, influence the electrical conduction system. Second, our pilot study seems to suggest that no adverse effects have to be expected immediately during heavy ion irradiation in performing subsequent experiments with doses of 30-60 Gy and intact pigs.

Treatment Planning Considerations for Robotic Guided Cardiac Radiosurgery for Atrial Fibrillation

“…While some groups are investigating complete non-invasive cardiac SRS with carbon ions [16, 17] or MRI-Linear-Accelerators [18], our goal was to analyze the general feasibility of cardiac SRS for paroxysmal AF in humans using treatment planning simulations and include possible options without fiducial implantation for the CyberKnife. The optimal non-invasive tracking method would be completely marker-less [19] which is already available for lung tumors for the CyberKnife [20].…”

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

“…We have recently provided initial data to ablate cardiac arrhythmias with ion beams in isolated Langendorff-perfused beating heart preparations121314. Our working hypothesis is that high-energy charged particles can be used to create chronic lesions that locally interrupt cardiac conduction and therefore enable treatment of heart rhythm disorders completely noninvasively while sparing surrounding tissues.…”

Leveraging Radiobiology for Arrhythmia Management: A New Treatment Paradigm?

“…As an alternative to causing structural fibrosis and producing ablative scar, a functional ablation may be achieved through acute and prolonged disruption of cardiomyocyte electrical conduction without cell death. Such an effect has been observed in large animal models at extremely high-dose treatments to the atrioventricular node that immediately produced complete atrioventricular block [86,87].…”