Histotripsy – a technique that harnesses soundwaves to attack cancer | Hacker News Reader

Histotripsy – a technique that harnesses soundwaves to attack cancer

news.engin.umich.edu

169 pointsrmason72 comments

Sounds interesting. I can only imagine what can be done if they can increase the resolution further so one can target tiny cell patches in the human body/living organism. Maybe even stop internal bleeding or more. Feels like Enterprise on the medical station. Being able to do this always reminds me I'm old and this is the future :D

Lets hope it makes noise in the future of medicine.

Contrary to what this press release implies, radiation treatments are focused too. The basic idea is that you use a rotating beam source with a center of rotation at the exact spot you want to treat. The beam delivers only a fairly modest dose to most of the surrounding issues because of its continual motion, but it always passes through the center, so the cumulative dose in that area is far higher. This image illustrates the idea:

https://patients.uroweb.org/wp-content/uploads/2018/12/Radia...

It's not perfect, and acoustic waves should have fewer side effects, but we already have the ability to selectively target a specific location inside your body.

I've had lithotripsy to destroy kidney stones. If the patches of cancer are smaller than that, then I can imagine it might be more difficult.

The trick with lithotripsy is that the stones have to be visible on a regular x-ray machine in order to be able to steer the beams of sound to the correct target. I don't know how you would detect the correct targets with cancer cells, at least not in an immediate feedback system that could be used by the doctors while the patient was on the table.

This is great news. My mom in law has lung cancer that has spread to her liver. I will pass along to ask her doctor!

http://web.archive.org/web/20231013193328/https://news.engin...

Had just read this other article earlier today... lots of sound therapy for cancer coming about! https://www.science.org/doi/10.1126/sciadv.adg5964

Definitely a great new modality

Benefits - Can target tumor noninvasively with active imaging. No damage of nearby blood vessels.

Cons - Sound waves can only penetrate a few centimeters into the body. Also need a liquid medium to travel, ie. Can't target brain tumors because of the skull, can't target lung tumors due to presence of air.

Can you just cut em open and use it on them there?

At that point you’d simply cut out the tumor.

Not necessarily. Maybe you can get to an organ but don't want to cut into the organ.

That's not accurate at all. A lot of tumors cannot be safely cut out or else they'd just cut out all tumors. Many climb around arteries and other critical areas.

Debulking most of the time isn't an option so if you can use this sound wave thing then that would be a game changer.

> Cons - Sound waves can only penetrate a few centimeters into the body.

For an Air -> flesh medium interface. I'd be very surprised if they didn't couple this to gel to have gel -> flesh interface for what is done with ultrasonography (e.g. imaging for pregnancy) and the article mentions that they do ultrasonography prior to make sure they know where to aim the energy so that would make sense.

In the video the tool looks huge, but I wonder if they could make a small version that could be inserted into the lungs like a scope.

It's an extremely good read and parts of it remind me of some sci-fi thing I read, maybe by Heinlein, about scientists pretending to have magic powers by designing a staff that manipulated things like sound.

It's hard to pick a pull quote, but let's go with this (below) and give notable mention to describing traditional treatments as a carpet bombing approach.

But histotripsy doesn’t need to understand cancer to be effective. Its reliance on physical force generated by sound means it can ignore questions like what turns normal cells malignant or why certain abnormal cells grow and spread in the body.

Therapeutic ultrasound in its many forms (non-/focused, low/high intensity, low/high frequency, non-/pulsed) seems to have potential in treating various conditions.

The latest I've heard about is research on low-intensity focused ultrasound (LIFU) in treatment of neurological and psychiatric conditions, e.g. https://www.frontiersin.org/articles/10.3389/fpsyt.2022.8258...

Comes off as snakeoil, just as ESWL and LiSWT are overhyped and largely ineffective.

Their sample size was only 44.

False hope in oncology is lethal.

A sample size of 44 can be fine if the effect is large enough. In this case the effect was pretty large, which is why they have FDA approval now.

> In contrast, radiation affects everything in its path through the body.

The ultrasound has to pass through the body as well, right? Is it that ultrasound can be generated across a broader surface and below a certain threshold has no impact? Or is there some other reason the above statement makes sense?

There was an article weeks ago about the distinction being that the ultrasound could be focussed in where it imparts energy. However I’m not finding what i remember or i’d link to it.

This technique causes cavitation at a precise depth. It's amazing.

https://www.youtube.com/watch?v=WqZLkzdNYuI - the video is 11 years old, from the same team. You can see them forming bubbles in precise shapes.

Could be that it's area of effect is only where the frequencies resonate.

That bit of the article seems incorrect... Alpha radiation dumps most of its energy in one region, according to the Bragg curve [1]

[1] - https://en.m.wikipedia.org/wiki/Stopping_power_(particle_rad...

I wonder if it's comparable to using a magnifying glass, in the sense that it's the hottest only at one specific point, even though the rays are traveling through the medium (air) at all points. So maybe it's like a magnifying glass for sound and the cancer is the ant that gets fried?

The ultrasound waves are mechanical, so the amplitude can be focused while radiation can not be.

Think of making to waves in the bathtub so that they collide in the center and splash. That would be an mechanical wave. On the other hand, radiation would be be like shining two flashlights from either sides of the sink. The light simply passes through itself.

That’s the basic idea. You’ll still get some heating of tissue as ultrasound waves pass through other tissue but won’t be destructive.

Radiation therapies use similar principles but non-target tissue is still exposed to ionizing radiation which causes collateral damage.

Saw some talks on this at the CIO meeting last month. Data so far is good but technique is limited to solid organs than can be targeted on ultrasound.

Regardless it’s an interesting treatment.

I'm curious to know how the soundwaves can be used to cause cavitation at a precise depth, while not causing cavitation along the entire wave pathway. Can anyone explain?

The wave would be focused by the transducer (analog of a lens) so that the energy flux is highest at the focal point and presumably low enough not to cavitate outside the focal area. I.e. magnifying glass and the sun kinda thing.

Makes sense but what if there's another organ in the way?

I think the way it works is you have sound from multiple sources, and you time the sound waves so that the peaks and troughs all hit the targeted area at the same time. Each individual 'beam' is harmless, but at the point of intersection they add up and can do damage.

David Gibson where ya at?? He’s been on this train for some time now with the Sound Healing institute in SF. Super neat stuff finally in a research environment.

It's not that kind of sound healing.

Could this result in those tumor cells spreading elsewhere in the body?

Not a doctor, nor do I play one on TV.

From the article, once the tumor is broken up the immune system begins to clean up the area and is able to learn antigens against the tumor. So your immune system would attack cells that are spreading around the body.

I think parent’s question was that, as metastasis occurs when tumor cells break off and move elsewhere in the body, is this likely to happen with the targeted areas.

I must admit I’d be curious to know this too as it seems like it could actually speed up terminal cancer if so (though I’m sure they’ve thought of that or I’m just really naive).

Ultrasound with a focus lens destroys the cells by creating cavitation (implosion 'bubbles') it does not move the tissue somewhere else.

It's basically the same as tumour tissue removal but without invasive surgery.

I think that would be a very real concern that will need to be evaluated post approval.

The approval was based on the device efficacy as a surgical tool for removing tumors, not as a treatment for cancer. Because of this, the trials did not look at long term outcomes like if the procedure leads to the cancer recurrence or spread.

In practice, The device will likely be used in conjunction with chemo, to try to hunt down metastatic cells.

In theory - maybe, sort of.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5380551/

I'm no expert either, but there seems to be a nonzero chance of that. However, according to the article, it is offset by the immune system learning of the contents of the destroyed cells and attacking these even elsewhere in the body.

I thought ultrasonic ablation was already a thing. Here's a paper from 2010: https://pubmed.ncbi.nlm.nih.gov/21358073/

It was in research, but now the FDA has approved it as a therapy. So I guess it takes 13 years to go from paper to clinic?

13 years is about right. a little on the long side for devices, but cancer trials are slow.

What an awesome use of cavitation - which can also generate heat at specific and precise point.

I'm surprised this wasn't thought about before. Seems like we've been advancing radiotherapy for decades, and forgot that ultrasonic transducer technology was free and clear to try the entire time.

https://en.wikipedia.org/wiki/Ultrasonic_cleaning#Design_and...

Lithotripsy has been used for kidney stones since the 1980s.

https://www.hopkinsmedicine.org/health/treatment-tests-and-t...

The unpopular theory is hat after Royal Rife argued that all diseases could be cured for 10 cents per person the industry went out of its way to kill it.

There are many nutty journalisms that dismiss it that never touch any of the publications or clinical trials.

Royal Rife advocated radiotherapy though, not this sonic stuff.

He was an engineer and toolmaker. Those do and build things then report findings.

The plasma tube has a mechanical component to it. The talk of RF online is odd, what would it grab onto?

> The challenge of the work is finding the right combination of frequenices, RF and audio rate, which will setup standing waves inside some part of the organism, in an attempt to 'devitalize' the organism's normal biological activities.

Destruction is also possible but devitalization is preferred.

Could this work against any/most cancers?

That's the impression I was getting from reading the article and other articles related to histotripsy. Still, it sounds too good to be true, so I'm wondering the same thing.

I was a little confused on why they can't use it on her other tumors that are growing in her liver.

It won't work for liquid tumours (i.e. blood cancers) since they "metastasise" to the whole vein/artery network.

Cancers in the brain/lungs/bone, unlikely, since the speed of sound is very different between bone/air and flesh. Though I could be wrong.

But for any solid tumour, it should work well.

Not every tissue passes ultrasound as well as the liver so it might need fine tuning for different tissues.

The liver also regenerates a lot faster which probably helps mitigate off-target effects.

According to the articles, it causes very little off-target damage.

Won't work for metastasized cancers for obvious reasons. Perhaps it will also be limited by bones just like regular ultrasound where their echoes produce shadows. I could be wrong though.

Ultrasound in general is also operator dependent: the skill of the human doctor matters. Limits scalability.

In rodent studies, it actually does help with metastasis. It breaks tumor cells apart in a way that makes them recognizable by the immune system, which goes on to kill other cancer cells throughout the body. We'll have to see what happens long-term in humans treated with it.

That was unexpected and really interesting. I hope the results turn out to be good.

Does anyone know of a good source of ultrasonic transducers of various kinds?

Digikey has a bunch

Does this only work on the liver? Not esophagus?

It might work on the esophagus. What's happening here is FDA is approving it for liver only. Perhaps that changes in the future.

Can you get the procedure without FDA approval?

Well, plenty of drugs are prescribed "off script". That is the medication is supposed to be prescribed for Ailment X but it's known to work for Z, and is used for patients with Z.

Are physical procedures the same? IDK. But of course, there might also be other countries that have the equipment and are willing to use it more broadly.

Outside the US that should be possible.

I love how this sounds (no pun intended).

Duty cycle and dosage duration?

This kinda info should be "open source".

Money needs to be motivated enough to investigate these kind of things

Research out of public universities should benefit everyone.

And it has. There is now a FDA approved device that can be used to treat people.

The government funds fundamental research because it believes that the public is better off with a device like this for sale than without one.

The government probably put some amounts of money, I'm guessing 100s of thousands, in grants to explore the technology. IT seemed promising so the commercial sector came along and invested 100s of millions. Crunchbase put the investment at 230 million in this case.

In addition to the sister comment (that I 100% agree with) that publicly funded research ought to be in the public domain, if the technique is broadly useful I’m sure that companies can find patentable optimizations to the equipment or protocol.

It's all in the papers, this is just a press release. See references here: https://histotripsy.umich.edu/

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