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Comment by mdp2021 | Hacker News Reader

mdp2021

Coincidentally, physicist Sabine Hossenfelder published on YT just hours ago about a new treatment - "proton flashes".

> one of the most common ways to treat cancer is radiation therapy with x-rays ... You can use these highly energetic photons to kill off cancer cells. The difficulty really is ... killing the cancer cells without killing the patient - but the problem with using x-rays is that you can't shoot them at tumors inside the body without also burning some of the tissue on the way to the tumor and behind it... But you can use beams of other particles instead and this is where particle physics enters ... A beam of protons is far less likely to interact with tissue on short distances

And it is still part of the "kinder" set (protons are "kinder" than x-rays).

New Cancer Treatment With Proton Flashes Goes on Trial

https://www.youtube.com/watch?v=K515uMQQzV4

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I actually worked with MGH on their first proton treatment software for non cyberknife proton treatment. Later scaled it into AWS so their dosimetrists could iterate on treatment plans much faster. The initial treatments were incredibly successful and much easier on the patient, but theres no miracle either.

Patients still suffer adverse reactions, and you will have margins of error, not to mention you do not have unlimited time to develop a treatment plan that is perfect. It's a time/efficacy trade off and the goal is to hit as much of the cancer as possible, while maintaining a SAFE dose of radiation, not a zero dose. What is a safe dose? Well, the more aggressive your cancer the higher that number gets too.

Some patients still receive high dose radiation while on proton treatment simply because their cancer is that aggressive, typically suffering the same grade 1-2 diarrhea and vomiting as any other form of radiation.

Proton treatment is far superior for most cancers, especially deeper cancers like colon and prostate.

It's a living example of how tragic a new treatment option is, unfortunately proton centers are expensive to build and take years. So many people are still passing away from treatable disease and having to endure high dose chemotherapy in other cases.

My theory is that cancer is a precision recall problem. Our body has the tools to fight cancer but they need to be precise otherwise they would end up attacking normal cells. Our cells do not have as much high level view that we do. On the other hand if we see a skin cell inside the brain we know that's cancer. Hopefully we can build some treatments that lets us light up cancer cells and have our own cells take care of it. That being said it's easier said than done

> Hopefully we can build some treatments that lets us light up cancer cells and have our own cells take care of it.

That's exactly what many of the new immunotherapies do.

MGH being Mass General Hospital or something else? I only ask because I'm a colon cancer patient at Mass General.

Yeah sorry Massachusetts General Hospital, we always used the abbreviation when talking about them.

Yea me too, I just didn't want to assume. that's awesome, maybe i'll ask about that when i come for my next chemo appt. :)

Worth noting here is that "proton flash therapy" is a new therapy, but "proton therapy" is not. Proton therapy is a lot more recent than x-ray therapy, but still a conventional therapy.

Flash therapy is the part is which just now entering clinical trials, where you treat the patient with ultra-high dose rates (so you deliver the same dose of radiation, but in maybe 90 ms instead of 90 seconds). There are indications that healthy cells are better at recovering from the ulra-high dose rate than tumor cells are, which means it would have a protective effect on healthy tissue, but the mechanism behind it is not known. The type of radiation is not specified, it can be protons, electrons, x-rays, etc.

So "proton flash therapy" is a Flash therapy that uses protons. Other clinical trials are using electrons instead, i.e. "electron flash therapy".

Thanks for explaining this, I'd heard of people being treated with proton beams already and it was pretty confusing to hear this was new and experimental.

What are the theories as to why healthy cells recover better than tumor cells, if any?

On the topic of interesting Physics contributing to new cancer therapies, there is also Boron Neutron Capture Therapy (https://www.neutrontherapeutics.com/about-bnct/). I gather the gist of it is that it builds up boron isotopes around a tumour, then bombards it with neutrons that mostly pass through the body but interact far more with the boron isotopes. Energetic particles are emitted, have a low range, and hopefully kill just the cancer cells. Apparently all in less sessions than with X-ray or proton therapy.

Disclaimer: I am not a doctor or medical physicist, I’m just fortunate enough to briefly use a machine intended for this purpose in separate nuclear physics studies. I believe BNCT has been done before with reactor sources of neutrons, but for some reason not as a standard treatment and there’s only one left in Taiwan for this purpose. The new development, afaik, is the ability to use accelerator neutron sources for this. Would love it if anybody knows more!

I asked my daughter the oncologist about this, and the better way of doing this is not to use boron as the payload, but rather some very powerful toxin. The toxin gets linked to a tumor-specific antibody. There are lots of targeted drugs of this kind being developed for various tumors.

Is there a way to like emit energy in a narrow beam from a bunch of different angles around a central target such that they only overlap in the center/target and the frequencies resonate in that location in such a way to reach a higher frequency past which there is a destructive effect but below which is safe and non-destructive?

/knows nothing about physics

Yes, there is beam forming.

Do a websearch about MIMO and beamforming, or ask Bing chatgpt to explain it.

They're generally delivered sequentially rather than simultaneously, but that is standard practice. It means you can concentrate the dose in the target area, but constructive interference affects only intensity, not frequency. And photons will still interact pretty evenly along the whole path.

https://en.wikipedia.org/wiki/Radiosurgery there is a subtype called Gamma Knife which uses a large collection of emitters to effectively target a location while keeping other locations under a specific radiation threshold.

I understand what you are getting at, but the short answer is no.

The longer answer is something called The Superposition Principle. Essentially, waves (photons) pass through one another. The amplitude adds, but only at the intersection. The frequency does not change. (Consider the laser as the ultimate example of this)

(Side note: The superposition principle does not always hold; however, the realms where the addition of MOAR PHOTONZ becomes non-linear are broadly incompatible with life)

So, most techniques involve having many, many beams intersect so that the individual paths are only a little damaged while a specific spot where they all meet takes the hit. I met someone who specifically programs the machines that do this because there's a lot of math involved chucking radiation around irregular hunks of blood, meat, and bone, and the calculations are done because the first idea of "just cross the streams" works fine in a vacuum, but not so much in the human body.

An inventor named Royal Rife experimented with destroying tumors by finding the resonant frequencies of the cancer cells.

I downvoted you mainly because Sabine is a font of misinformation in areas outside her direct expertise.

Particle beams for cancer therapy aren't new; shortly after the invention of the cyclotrone, EO Lawrence did this with neutrons in the late 1940s and proton beams were being used successfully in the 50's. She leaves out these details and only mentions trials from the 1990s.

> I downvoted you mainly because Sabine is a font of misinformation in areas outside her direct expertise.

Just curious, since I've run into her channel recently and found her generally pleasant and informative (minus the unfunny jokes part), do you have any specific examples of this?

https://www.reddit.com/r/AskPhysics/comments/15o0fx7/i_just_...

To be fair, her criticism isn't that LIGO itself was fake, but it's really hard to tell, from the video and from https://backreaction.blogspot.com/2019/09/whats-up-with-ligo... If you read that blog, you can see she is using a collection of rhetorical techniques to cast down on the LIGO results (for example, using the term retraction out of context).

But it's mainly her videos about health-related stuff that doesn't have good support. She approaches most of these things with a "assume a spherical cow" approach, common when physics folks try to do biology.

Thank you for the warning about Dr. Hossenfelder and for the information about the technology,

but we have not effected any blind endorsement. Just informed of a consistent parallel piece, esp. after the coincidence, which may be useful in itself - or just interesting.

Let me guess without looking at the video. Is it about the Bragg curve?

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