Thermal Ablation of Biological Tissue by Sonicating Discrete Foci in a Specified Volume with a Single Wave Burst with Shocks

New protocols have been developed of biological tissue volumes with shock-wave bursts using trajectories uniformly filled with discrete foci within a given volume. Each focus was sonicated with a millisecond-long pulse, which immediately generated a single thermal lesion. In developing the most advantageous irradiation protocols, the effect of the source peak power at a constant time-averaged value, the distance between single foci, and geometry of the outer contour of the trajectory on the shape, volume, and thermal ablation rate was analyzed. It is shown that for an arbitrary geometry of the outer contour of a single-layer trajectory, the most advantageous is the saturation mode of the shock front amplitude at the array focus using a trajectory with a spatial step 1.5 times greater than the transverse size of the single lesion. To obtain thermal ablation volumes on the order of cubic centimeters, protocols have been suggested with layer-by-layer irradiation of tissue, which make it possible to accelerate the thermal ablation process by 2.5 times compared to protocols used in clinical practice. The advantage of the proposed protocols that use the shock-wave exposure is the ability to generate localized and predictable thermal lesion without using MRI temperature monitoring.