This is the cool part:

But histotripsy foils cancer’s cloaking efforts by destroying its cell walls, leaving the tumor antigens in plain sight for the body’s immune system.

This effect was detailed in a pair of papers published by the U-M research team between March 2022 and January 2023. They demonstrate that the sound waves used to break down cancerous tumors in rats also helped trigger the rats’ immune response. After histotripsy destroyed 50% to 75% of liver tumor volume, the rats’ immune systems cleared away the rest, with no evidence of recurrence or metastases in more than 80% of animals.

That immune response occurred throughout the body, not just in areas targeted by the histotripsy treatment, resulting in the reduction of tumors far from the treated area.

The immune response is key. Without it, histotripsy is just yet another way to destroy a tumor without curing the cancer.