A new technique that destroys cancer using soundwaves also spurs the immune system to kill off any of the tumour left, scientists have revealed. The non-invasive treatment only needs to be partially effective to stop the cancer spreading.
It is currently being tested on human liver cancers in the US and Europe following successful trials in rats. The team from the University of Michigan showed the noninvasive sound technology is able to prevent further spread with no evidence of recurrence or metastases in the majority of cases.
The treatment, called histotripsy, noninvasively focuses ultrasound waves to mechanically destroy target tissue with millimetre precision. In many cases, the entirety of a cancerous tumour cannot be targeted directly in treatments due to the mass' size, location or stage.
However researchers investigated the effects of partially destroying tumours with sound to 50 or 75 percent and found the technique was still very effective. They showed that in 80 percent of cases performed on rats, the immune system broke down the rest of the tumour and it did not return.
Professor Zhen Xu, at the University of Michigan, said: "Even if we don't target the entire tumour, we can still cause the tumour to regress and also reduce the risk of future metastasis. Our transducer delivers high amplitude microsecond-length ultrasound pulses—acoustic cavitation—to focus on the tumour specifically to break it up.
"Traditional ultrasound devices use lower amplitude pulses for imaging."
Tejaswi Worlikar, a PhD student in biomedical engineering, said: "Histotripsy is a promising option that can overcome the limitations of currently available ablation modalities and provide safe and effective noninvasive liver tumour ablation. We hope that our learnings from this study will motivate future preclinical and clinical histotripsy investigations toward the ultimate goal of clinical adoption of histotripsy treatment for liver cancer patients."
The study was published in the journal Cancers.
