When Mike Blue, the CEO of HistoSonics, is asked to describe his company’s technology, he doesn’t start with ultrasound physics or FDA clearances. He starts with a woman named Emma.
Emma, a mom in her mid-fifties, was living in Wales when she was told she was terminal. Her cancer had spread to her liver—22 tumors in total—and the prognosis was clear enough that she began preparing her young children for the possibility that she might not survive. Surgery wasn’t an option. Chemotherapy had failed. There was nothing left to try.
Through an online patient community, Blue says, Emma learned about histotripsy, a noninvasive ultrasound treatment available in the United States that mechanically destroys liver tumors without surgery, radiation, or chemotherapy. She traveled overseas for care. After three treatments, all 22 tumors in her liver became necrotic—dead. She went from planning for the end of her life to returning home alive, stable, and without detectable liver tumors.
Blue shared Emma’s story with Gwyneth on a recent episode of the goop podcast, in a conversation shaped as much by lived experience as by innovation. Gwyneth has spoken openly about watching her father endure aggressive cancer treatments—interventions that helped prolong his life but were physically devastating. So, when Blue describes histotripsy, a method that uses focused ultrasound energy applied from outside the body to break tumors down at a cellular level, the contrast is immediate.
After more than 20 years in development, histotripsy is now FDA-cleared for the treatment of liver tumors, including metastatic disease. Instead of burning or poisoning tissue, it allows the body to clear destroyed tumor material naturally. It is noninvasive and non-toxic, with minimal side effects—qualities that have made it especially compelling for patients who have been told they’ve exhausted conventional options.
What animates the conversation is timing. If a treatment can eliminate tumors without compounding suffering, why do patients like Emma so often encounter it only at the end of care? And what would cancer treatment look like if relief, rather than endurance, guided intervention earlier in the disease course?
For now, patients like Emma remain the proof point—arriving at the end of the line and leaving with time they were told they no longer had.
In the episode, Gwyneth and Blue discuss how histotripsy works, how it’s already being used, and what it could mean for the future of cancer treatment.
Gwyneth Paltrow: For people listening who have never heard this term before, what exactly is histotripsy?
Mike Blue: Histotripsy uses therapeutic focused ultrasound. Most people are familiar with diagnostic ultrasound—you use it to look inside the body. Therapeutic ultrasound is much higher power. We deliver that energy from outside the body to a very precise point inside the body, where it creates pressures that break down tissue at a subcellular level. The tissue basically liquefies, and then the body knows how to process and remove it naturally over time. So we’re removing unwanted tissue completely noninvasively.
GP: When you say unwanted tissue, are we talking about cancer?
MB: Cancer is where we started, but it’s not limited to cancer. We’re FDA-cleared right now to treat liver tumors, and we’ll be submitting data soon for kidney and pancreatic tumors. Beyond that, we’re working on benign prostate disease, uterine fibroids, and neurological conditions. The mechanism is the same—we’re targeting and breaking down tissue without cutting into the body.
GP: What is it actually approved for today?
MB: The FDA has cleared histotripsy for the noninvasive destruction of liver tumors. That includes primary liver cancer, but a large percentage of patients we treat have metastatic disease—breast cancer that’s spread to the liver, for example.
GP: I lost my dad to cancer, and I was with him through all of it—the surgeries, the radiation, the chemo. The side effects were brutal. Sometimes it felt like the treatment was almost as hard on his body as the disease. When I hear about something that doesn’t involve cutting or poisoning the body, it feels like a completely different way of thinking about care. Where does this fit into cancer treatment right now?
MB: Surgery is still considered the gold standard when it’s an option. The reality is that about 80 percent of patients with liver tumors aren’t surgical candidates. Those patients are left with radiation, ablation, or chemotherapy, all of which come with real trade-offs. Most of the patients we treat today are more advanced—people who’ve been told they don’t have many options left, or who’ve already been through other treatments and are dealing with recurrence.
GP: That was very much my experience—watching how limited the options became over time. Why do you think so few people know about this?
MB: Medical devices are regulated very differently than drugs. If this were a pharmaceutical, we’d be required to run massive phase-one, two, and three trials, and by the time it launched it would be everywhere. Devices are often treated as tools by the FDA, so the focus is on safety and short-term effectiveness rather than long-term survival data. We’ll build that longer-term evidence over time, but it isn’t required to begin treating patients.
GP: What are you actually seeing in people who get histotripsy?
MB: The safety profile really stands out. It’s noninvasive and non-toxic, and most patients have very few side effects. Many people—especially those with advanced disease—feel relief from pain almost immediately, because you’re reducing the pressure the tumor is putting on surrounding tissue. For some patients, just feeling better physically is huge. And in some cases, we’ve seen things that suggest an immune response, where tumors we didn’t treat directly also start to regress.
GP: Can you explain that a little more?
MB: Histotripsy causes what’s called programmed immunogenic cell death. When we break down a tumor, antigens are released and absorbed by the body. In animal models—and in some human cases—that seems to activate the immune system. It doesn’t happen for everyone, but when it does, it can be really meaningful.
GP: That idea—that treatment could work with the body instead of constantly attacking it—feels so different from what so many families have lived through. Could this be used earlier, before things get so advanced?
MB: Yes. There are millions of people under surveillance for small nodules—watch-and-wait situations. Because histotripsy is noninvasive and has so few side effects, there’s a strong argument for treating those lesions earlier instead of waiting to see what happens.
GP: Where in the body can this be used?
MB: Technically, almost anywhere. The lungs are more complicated because air blocks ultrasound, but we’re working through that. We’re advancing programs in breast, thyroid, bladder, spine, brain tumors, and uterine fibroids. The system was designed to treat the whole body.
GP: Is it painful?
MB: Most people feel little to no pain. Some have temporary soreness—similar to muscle fatigue—that goes away within a day or two. Compared to surgery, radiation, or chemotherapy, it’s very minimal.
GP: What’s next for you?
MB: We’re submitting data for kidney and pancreatic tumors this year and accelerating work across multiple indications. With the funding we’ve raised, we’re able to move much faster than we could before.
GP: And for anyone listening who’s dealing with cancer—or supporting someone who is—where can they go to learn more?
MB: Histosonics.com. There’s a physician locator, and people can also reach out to us directly. We help navigate these questions every day.