Posted by 1659447091 6 days ago
This method of ultrasound treatment is called histotripsy. The underlying mechanism it uses to treat tumors is by focused ultrasound beams that mechanically disrupt cell membranes . It basically turns the lesion into soup. It does not treat the lesion by heating, although there are other techniques that do use ultrasound to ablate tissue with thermal energy.
Where I have seen it used and discussed is in the liver, whether that be metastatic disease to the liver or primary liver tumors.
One challenge is that in the liver you can’t use it for lesions that are near the capsule of the liver. It can also be difficult to keep the ultrasound beam focused on the lesion with respiration, especially if the tumor is small.
It’s an interesting technique and I think more people will use it over time. Whether it will be better than other established techniques like microwave ablation or radioembolization (for liver tumors) remains to be seen. I’m an interventional radiologist.
They showed us results of HIFU applied to real patients to non-invasively ablate tumours and treat prostate issues. As far as I can tell the probe creating the ultrasonic waves needs to be relatively close.
A thought I had at the time was if you knew all of the material properties of all of the tissues inside someone and their locations (say with an MRI) you could in theory apply this even deeper in someone than is currently possible - with a larger stick-on patch of actuators as a phased array.
Finally, another memorable thing that was discussed was what another researcher was doing with ultrasonics. Stride (who I am delighted to say was a fantastic lecturer) was very interested in bubbles. She would construct tiny bubbles where the surface (or interior?) was made of a chemotherapy drug. These bubbles could then be injected into someone's blood stream and would be ruptured using ultrasound to allow for extremely targeted application of chemotherapy (the jet formed from rupture would be so strong it would inject the drug into nearby tissue).
Fascinating, fascinating stuff but of course developed over many years of hard work.
This reminds me of Feynman s spinning plates.
It also drives home the serendipity of science. One can easily pander a researcher spending their days thinking about bubbles from a place of ignorance. Yet this is what basic research often looks like—play.
Is prostate size reduction possible?
Well said. And it's either terrible or expensive (and sometimes also terrible as well).
Proton therapy for instance is amazing at targeting hard to reach tumors like those in the eye, but costs close to fix figures as it requires a team of people to design the treatment.
For comparison, a liver histotripsy costs $17.5k:
https://histosonics.com/news/histosonics-notches-significant...
Not a bad deal for a non-invasive life-saving surgery.
I looked into it deeper at the time and it's very difficult to untangle the true cause of death in many of these situations. While certainly these treatments are ultimately beneficial statistically, it is concerning that there's not as much discussion around their harm and the real risk rewards behind various treatments. I know from my own (non-cancer) experience that there is a very strong bias towards treatment even in cases where, once you break down all the risk and rewards, there is a strong argument for non-intervention.
Here in Canada, before assisted suicide was legalized, my grandfather (in his late 80s) refused any treatment for his kidney failure. He was ready to die and could barely walk or eat on his own anymore. There was a wink wink situation where as the kidney failure worsened, his morphine was increased to the point where it was fatal. The death certificate still said renal failure, though.
For me, if I ever got terminal cancer, I'd weigh the quality of life of treatment versus non-treatment. I've seen people go both ways and I've seen the results being right and wrong both ways. I don't want to spend my final months semi-alive on a bed or constantly messed up, though.
Not my experience. I have a loved one going through cancer treatment right now and they've been very up front about risks, side effects, and even talked about DNRs with them what they mean and how they can be applied.
People and their loved ones don't want to experience death. It's often as simple as that.
> There was a wink wink situation where as the kidney failure worsened, his morphine was increased to the point where it was fatal.
In the US, exactly because of situations like this, that sort of thing is a lot harder today to pull off.
> I'd weigh the quality of life of treatment versus non-treatment.
Something to consider, it's not a binary and treatment can look entirely different depending on the cancer.
You can, for example, do a lower than effective dose of chemo which will still be effective at slowing the growth of cancer.
Some therapies, such as immunotherapy, can be practically a walk in the park.
I'd suggest strongly in any case that you have a discussion with an oncologist if you ever get to that point. Things in medicine aren't nearly as black and white as people sometimes assume.
HIFU for prostate also is a ripe area for grifters as it is advertised and marketed towards low risk cases that would probably benefit from active surveillance.
Unfortunately, I have extensive first hand experience with practices that do this, and you are 100% correct.
The grift is very insidious. If you scan people over a certain age with prostate MRI, you will find suspicious lesions in a large percentage. And using fusion MRI/US guided biopsies, you will inevitable get cancer cells in the sample.
Many (most?) of these people being treated will die WITH prostate cancer, not FROM prostate cancer.
I don’t actually know much about them, I just heard of them because their CEO (Mary Lou Jepsen, she’s quite famous, right?) was on the AMC podcast (months ago, actually, I was just going randomly though the back catalogue).
Tech folks pivoting to medical always throws off some alarm bells to me, but she was fairly compelling on the podcast and the basic idea seemed to make sense. Ultrasonic treatments, using diagnostic-level energies, using focusing and resonance based tricks, I guess. (It is way outside my wheelhouse, sorry if the description is inaccurate).
The best way to evaluate biotech startups from the outside is to look at their investors. If they’re full of VCs specializing in biotech, chances are someone did the bare minimum due diligence on the science.
Theranos for example didn’t have a single one because biotech VCs steered clear of that mess entirely.
Same for me. I've been in the medical device industry for 15+ years now and came from "tech". What a lot of techies under/don't appreciate is that the medical device industry is heavily regulated and moves at a muuuch slower pace than other technologies.
There are lots of regulatory and quality/testing hurdles that you must clear (namely verification and validation testing, in addition to your 510(k) clearance or approval, if PMA) before you can market and sell your device.
I tell customers, on average, a Class II medical device project can take 18-24 months and cost $3M to 4M, minimum.
“Our tech-driven approach leverages software, hardware and AI […]
That means we can iterate at the speed of consumer electronics”
Which is kind of scary but also a bit interesting.
How would you go about regulating an open source medical device? The user can just plop whatever software on there that they want, and ultrasound themselves wherever… play with resonance and focusing, right?
The manufacturer will still need to validate their own firmware and subsequent updates. Whether it’s open source or not doesn’t matter because a huge part of the approval process is quality control tied to a specific manufacturer.
Anyone who plops their own software will be liable for the consequences and I doubt malpractice insurance would allow it in the vast majority of cases.
I was aware of her from the OLPC project and the cool Pixel Qi screen tech from that, but haven't watched the talks.
Fun fact: using this ultrasound for prostate cancer treatment reduces the risk of erectile disfunction
Yes you can. If you had an array of ultrasonic transducers around the body you could have each of them in phase targeting a single spot. Beamforming is a thing we've been doing for years with RF. It's even more trivial with sound.
You just gotta catch the right wave
I’m not aware of strong evidence in this area (not saying you’re incorrect).
For the liver indications, several elite radiology departments have had very poor outcomes with their patients, despite the strong public data. I would not, with my own prostate, try a new technology until at least a decade out, at least.
This technology is also now used to treat non-cancerous prostate enlargement (BPH).
There are other options besides prostatectomy or the untested histotripsy.
Histotripsy is early in its clinical life but I wouldn't say untested.
People who aren’t in medicine are very susceptible to advertising - this is why I’m writing so stridently
And a review: https://pubmed.ncbi.nlm.nih.gov/36686753/
He did an evaluation about getting one for my local hospital.
https://news.ycombinator.com/item?id=31630679
Apparently, only some tumors have a distinct and unique shape / size. The “trick” is to calibrate the resonance exactly to the size of the cancer cell. So that resonance would “hurt” only that kind of shape / size cell. Which was much harder to do than it sounds. Sadly not all cancer cells are unique and not that “easily” distinguishable by size
But I am not in the medical field and just repeating what I’ve read.
Watching Hank Green's YouTube video where he found out that his cloudy pee was cancer leaving his body, he was surprised that doctors don't tell you to expect it. It can be such a morale boost.
> Some researchers have raised concerns about histotripsy potentially seeding new cancer growths as tumours are broken up inside the body, meaning they can be transported to other areas. That fear, however, hasn't borne out in animal studies so far.