Histotripsy versus thermal ablation

The brief

Is histotripsy an improved treatment for cancer tumours compared with thermal ablation techniques?

What I did

I compared four thermal methods (radiofrequency ablation, microwave ablation, cryoablation and high-intensity focused ultrasound) on mechanism, guidance method and failure mode, then compared them with histotripsy.

Thermal methods share a limitation called the heat-sink effect: near large blood vessels, blood flow carries heat away, which reduces effectiveness and can mean more treatment sessions. Histotripsy is mechanical rather than thermal. It uses short ultrasound bursts to cause cavitation, whereas HIFU uses longer bursts at a duty cycle above 10% to heat the tissue. As a result, the heat-sink effect does not apply.

I also traced how the technique developed: cavitation was first seen as an unwanted side effect of HIFU, then studied deliberately as shock-wave therapy, and then developed into histotripsy.

Result

A preliminary report, final report, key diagram, presentation outline and delivered presentation, plus a separate ethics report on the technology.