The technique, called histotripsy, generates exploding bubbles to kill tumors
Minneapolis-based HistoSonics, founded in 2009, pioneered the treatment
By CAITLIN TILLEY, HEALTH REPORTER FOR DAILYMAIL.COM
PUBLISHED: 16:47 EDT, 17 October 2023 | UPDATED: 17:39 EDT, 17 October 2023
A promising cancer treatment that blasts tumors using soundwaves has been approved in the US.
A machine that uses histotripsy, a technique that uses sound waves to break down tumors, has been approved to treat liver tumors by the US Food and Drug Administration (FDA).
It uses targeted sound waves – like an ultrasound machine – to form microbubbles within the tumor.
The forces generated as the bubbles expand and collapse rapidly cause the cancerous mass to break apart, destroying tumor cells and leaving the debris to be eliminated by the immune system.
The approval of the treatment means patients may be able to get treatment for liver cancer without the side effects of radiation or chemotherapy.
Minneapolis-based HistoSonics, a University of Michigan spin-off company founded in 2009, pioneered the treatment.
HistoSonics can now sell its histotripsy delivery platform, named Edison, to hospitals and doctors to use in patients. It costs $12,500 per procedure.
The procedure is performed under general anesthesia and is done alongside a live ultrasound of the liver to enable the radiologist to locate and blast the tumor.
A bedside machine with a robotic arm is moved into position over the patient’s abdomen like a traditional ultrasound device, and a doctor locks it above the target tumor.
The rest of the procedure is fully automated.
Attached to the end of the robotic arm is a transducer, a device that converts electrical energy into ultrasound energy.
The machine’s software then calculates how much energy is needed to create a powerful enough bubble cloud to kill the tumor, with focused ultrasound waves converging at a focal point in its center.
Once the debris of the tumor has been liquified, it will be naturally absorbed in the body before it is passed out as waste.
The debris created becomes scar tissue.
Although it’s considered a safe treatment, there is a small risk nearby blood vessels (or in the case of liver cancer, bile ducts) could be damaged by the heat.
The duration of the procedure depends on the number and size of tumors, but it can take as little as seven minutes.
A human trial is currently underway, and previous animal studies have shown promising results.
In the first study, 50 to 75 percent of liver tumor volume in rats was destroyed by histotripsy and the rats’ immune system cleared away the rest. No tumors recurred or spread in more than 80 percent of the animals.
A second study showed the sound waves also break down the cancer cell wall’s ‘cloak,’ revealing proteins the immune system can use to recognize threats.
By killing the cancer cell’s outer wall, the tumor’s antigens are laid bare for the immune system to use for targeted attacks on other cancer cells to prevent recurring tumors.
A trial in humans has been underway since 2021 at the University of Michigan Rogel Cancer Center and other locations have treated patients with both primary liver tumors and liver cancer tumors that have spread beyond the liver.
Zhen Xu, University of Michigan professor of biomedical engineering, inventor of the histotripsy approach and a co-founder of HistoSonics, said: ‘We want to leverage histotripsy’s immuno stimulation effects and hopefully combine them with immunotherapy or drug delivery.
‘That will move histotripsy from a local therapy into one that can treat tumors globally all over the body and eventually into a cure. In terms of the cancer treatment, that will be the next step, and I feel very excited about the potential.’
Despite the new promising treatment, cancer patients shouldn’t expect to immediately do away with their chemotherapy and radiation treatments.
The machine has only been approved for use in liver cancer patients, and its limited availability and high price tag may make doctors prescribing it to patients prohibitive.
While the machine is a breakthrough in treatment, it may not be suitable for every liver cancer patient, and doctors will assess each case and determine the best course of action.
Liver cancer is the third leading cause of cancer-related deaths in the US. According to the American Cancer Society (ACS), the average five-year survival rate for all stages is 20 percent.
More than 40,000 live cancer cases will be diagnosed in 2023, the ACS predicts, and almost 30,000 people will die.
Drinking alcohol can raise the risk of liver cancer.
Histotripsy could be used in the future to treat renal and pancreatic tumors, Edison’s makers said.