Patient-Specific Cardio-Respiratory Model for Optimization of Cardiac Radioablation

Stereotactic Arrhythmia Radioablation (STAR) is a promising treatment for refractory ventricular tachycardia. However, its precision may be hampered by cardiac and respiratory motions. Multiple techniques exist to mitigate the effects of these displacements. The purpose of this work was, based on cardiac and respiratory dynamic CT scans, to generate a patient-specific dynamic model of the structures of interest, that enables simulation of treatments for evaluation of motion management methods. Deep learning-based segmentation was used to extract the geometry of the cardiac structures, whose deformations and displacements were assessed using deformable and rigid image registrations. The combination of the model with dose maps enabled to evaluate the dose locally accumulated during the treatment. The reproducibility of each step was evaluated considering expert references, and treatment simulations were evaluated using data of a physical phantom. The exploitation of the model was illustrated on the data of nine patients, demonstrating that the impact of cardiorespiratory dynamics is potentially important and highly patient-specific, and allowing for future evaluations of motion management methods.