"Radiation therapy does cure cancer, but it does also cause a lot of long-term side effects," Sharma says. If its effects can be enhanced thanks to ultrasound-stimulated microbubbles, she says, doctors could theoretically use lower doses to achieve the same treatment effects with fewer devastating side effects. 

Ultrasound also seems to be a good match for immunotherapy, a treatment approach focused on spurring the immune system to fight off cancerous cells that may be dodging or hiding from the body's natural defences.

As focused ultrasound heats and damages tumours, it seems to make these tissues more visible to the immune system – and thus more vulnerable to its defences, says Price, whose research centre is focused on using ultrasound along with immunotherapy. 

A direction for future research, Price says, is determining whether that pairing can work against advanced-stage cancer. Metastatic cancer is much harder to treat than localised disease – when cancer spreads throughout the body, it's no longer enough to remove a single tumour. The holy grail would be that clinicians could someday use ultrasound to coax one tumour out of hiding by breaking it apart, allowing the immune system to pick up on its characteristics and launch a system-wide attack against cancerous cells elsewhere in the body, Price says. This remains to be tested in any kind of trials, but theoretically, doctors could "treat 10, 15, 20 tumours just by treating one tumour", Price says.