Aberration correction expands the treatment envelope for histotripsy in the liver

Objective.Histotripsy is a non-invasive, non-thermal, and non-ionizing tissue ablation method based on high-amplitude pulses of focused ultrasound that has been approved by the federal Food and Drug Administration for the treatment of liver tumors. However, histotripsy currently cannot treat all locations in the liver due to attenuation of the pressure amplitude at the focus by sound-blocking ribs and air pockets and by phase aberration, or de-focusing of the ultrasound pulses by heterogeneous bodily tissues. Previous work suggests that correcting for phase aberration could increase the focal pressure to expand the treatment envelope (the treatable region) for histotripsy in the liver. The objective of this study was to investigate the effect of aberration correction on the treatment envelope.Approach. Acoustic propagation was simulated in the human body using a linear model (k-Wave) for a histotripsy phased array of similar dimensions to the current Histosonics Edison® clinical device and anatomical data from 10 subjects of varying body size.Main results. We find that aberration correction increases the focal pressure throughout the liver to substantially expand the treatment envelope (from 67% to 81% of the liver volume, on average, by linear estimations).Significance. The study suggests that aberration correction could help enable non-invasive, non-thermal histotripsy treatments for a broader patient population.