Sound waves are being harnessed to break down cancers.
The technique—known as histotripsy—breaks apart tumors and makes them visible to the immune system, which can then mount a defence against the cancer.
It’s been developed by the University of Michigan, and is being tested in the Hope4Liver clinical trial and has been successfully used alongside brain cancer therapy and immunotherapy.
In a new study, the Michigan researchers have discovered how histotripsy triggers an immune response to the cancer. With chemotherapy and radiotherapy, the entire cancer cell, including proteins known as tumor antigens, are destroyed, while histotripsy opens up the cancer cell wall to reveal the antigens, which alerts the immune system.
In tests on laboratory rats with liver cancer, the tumors were completely destroyed, even when only half the mass was targeted by the sound waves. The immune response stopped the spread of the cancers in more than 80 percent of cases.
In a separate study with mice, the Michigan researchers were able to transfer the cancer cells exposed to the sound waves into other mice, and these also triggered an immune response in the second mouse. “Injecting the debris into a second mouse had almost a vaccine-like property. Mice that received this debris were surprisingly resistant to the growth of cancers,” said Zhen Xu, one of the researchers.
The university has been developing histotripsy since 2001.