Dual-focus scanning in volumetric HIFU ablation: Preliminary simulation study

Volumetric HIFU ablation has been implemented in clinical practice to create large thermal lesion while reducing treatment durations. However, it still takes several hours to cover the whole target using volumetric ablation. Multiple focus intensity patterns have been proved beneficial to create larger lesions. The feasibility of dual-focus scanning in volumetric ablation has been evaluated. Simulations of dual-focus scanning and single-focus scanning were performed with the treatment cells of 4, 8, 12 and 16 mm in diameter. Comparison of both scanning approaches indicates that the dual-focus scanning saves treatment time by 20% and needs lower peak acoustic pressure, therefore the potential cavitation could be avoided. Although the maximum near-field temperatures are slightly higher than single-focus scanning, they are acceptable in HIFU treatment.