[nicwilson]

It won't work for liquid tumours (i.e. blood cancers) since they "metastasise" to the whole vein/artery network.

Cancers in the brain/lungs/bone, unlikely, since the speed of sound is very different between bone/air and flesh. Though I could be wrong.

But for any solid tumour, it should work well.

[pazimzadeh]

Not every tissue passes ultrasound as well as the liver so it might need fine tuning for different tissues.

The liver also regenerates a lot faster which probably helps mitigate off-target effects.

[DennisP]

According to the articles, it causes very little off-target damage.