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FLASH radiotherapy's bold approach to cancer treatment
- tiderpenger 7mo agoI generally don't trust cancer-communication if it's juiced up like this incredible headline. There has been huge amounts of progress. We don't need silicon valley idiots starting to make proclamations. It's doing fine without your mediocrity.
- jjtheblunt 7mo ago(they're French, not Silicon Valley)
- bitwize 7mo agoSounds a little too close, in both name and concept, to Therac for my comfort.
- NetMageSCW 7mo agoHow superstitious are you? Do you avoid black cats and ladders?
- hinkley 7mo agoWhen corporate arrogance is involved we called it Bayesian inference not superstition.
- doubled112 7mo agoI avoid any strange animal and walking under ladders. Those aren’t superstition, just common sense.
- taneq 7mo agoI wouldn’t call a ship “Titanic”.
- Eduard 7mo agoTheryq - why would they go with this name when everyone in the field knows about the Therac-25 radiation overexposure incidents?
- bilbo0s 7mo agoExactly what I thought as soon as I learned the name. It's like, man, how to kill a product? No pun intended. It could even work? But you put yourself behind such a poorly placed 8 ball when you do these things. Even among researchers, people are a little superstitious about stuff like this. It's always in the back of everyone's mind.
- leptons 7mo agoI doubt any of that is valid. Therac-25 happened 44 years ago, that's a very long time, and many people involved in cancer research today weren't even alive when it happened. "Theryq" and "Therac" are not quite the same either. The word "therapy" and derivatives of it using "thera" are still used widely across the medical industry. So I'm not really sure why anyone here is making a big deal about the name of the company being "Theryq".
- hinkley 7mo agoIt’s an s-tier case study for UX research though. Maybe the doctors don’t remember but we do.
- Aurornis 7mo ago> Even among researchers, people are a little superstitious about stuff like this. Being superstitious is not common in the medical treatment world, where weird product names are common. A doctor isn’t going to include the device’s brand name in their decision process for treating a cancer patient. The Therac-25 case study is noted in the medical world but not to the same extent as in engineering. The case was a tragedy of bad engineering, but the doctors involved in directing the treatments were not at fault for the radiation over exposures.
- 7mo ago
- scythe 7mo agoHey, FLASH finally hit Hacker News! I remember my professors talking about this in graduate school. It's a fairly well-established effect: the tumor selectivity of radiation is much better at ultra-high dose rates. It is still unclear exactly why. But there are a lot of studies about it: https://www.nature.com/articles/s41571-022-00697-z https://www.nature.com/articles/s41571-022-00697-z
- LoganDark 7mo agoMy guess would be that the radiation doesn't itself care but that tumors have some other characteristic (like multiplying rapidly) that makes them more susceptible to it. Similarly to how you can sometimes attack them with medication that inhibits cell division.
- scythe 7mo agoYeah that's the conventional dose rate effect, not the FLASH effect. The FLASH effect happens on timescales so short that ordinary considerations like the cell cycle or DNA repair mechanisms are inherently ruled out. Instead it might have to do with the type of radical species that form in normal cells versus tumors, possibly related to oxygenation, pH, glycolysis byproducts, etc. The first interaction of radiation with tissue is usually this: H2O + ħv >> H2O+ + e- (fugitive) The radical ion H2O+ is extremely reactive and usually protonates another water molecule immediately: H2O+ + H2O >> H3O+ + OH* The hydroxyl radical has a half life of about a nanosecond and will usually be the main "reagent", diffusing until it runs into an organic molecule which will be oxidized and thus degraded. At high enough dose rates, the peak concentration of hydroxyl radicals and more stable radicals like superoxide could be much higher, leading to "nonlinear" effects, i.e. byproducts of multiple radicals interacting with each other or a protein.
- slibhb 7mo ago> Currently, the most plausible theory emerging from her team’s research points to metabolism: Healthy and cancerous cells may process reactive oxygen species—unstable oxygen-containing molecules generated during radiation—in very different ways. Reminds me of this which I (think) was linked here a while ago: https://www.nature.com/articles/s12276-020-0384-2 https://www.nature.com/articles/s12276-020-0384-2 It really does feel like all these piecemeal cancer treatments are converging on something resembling a cure.
- hinkley 7mo agoThere was also a study that showed that chemotherapy efficacy was enhanced by fasting before treatment. It seems that when calories are scarce, healthy cells turtle up while cancer cells keep consuming, so fasting reduces absorption rates in healthy tissues and thus collateral damage.
- sl_convertible 7mo agoHealthy cells CAN turtle-up, whereas cancer cells engage in unregulated reproduction. Also, some cancer cells can only consume glucose. Which, in a fasted state, would mean that the majority of energy would be in ketones(if the individual were metabolically healthy), starving the cancer cells to death.
- arijun 7mo agoWhy wouldn’t a strict keto diet not be a cure for those cancers?
- amelius 7mo agoWhat is the intensity at the focal point versus areas surrounding it?
- hinkley 7mo agoI recall someone was analyzing the refractive index of various tissues in order to tighten the target area for multi beam radiation therapy. Particularly for brain cancers. By hitting from multiple angles the dosage in surrounding tissues is lower, and by calculating how the head lenses the beam you reduce the high dose area in the middle, like a 3d Venn diagram. But I don’t remember is whether that experiment became SOP or not.
- the8472 7mo agoThe sidebar mentions heavier particles having a pronounced Bragg Peak[0] and also existing approaches like multi-beam targeting. The FLASH effect in the article is yet another tool to limit the surrounding damage. [0] https://en.wikipedia.org/wiki/Bragg_peak https://en.wikipedia.org/wiki/Bragg_peak
- mv4 7mo agoDoes this have to do with cell division?
- hinkley 7mo agoCellular metabolism from the look of it. Cellular division and metabolism are linked but not synonymous. However that’s the current theory, of a long line of theories that did not pan out.
- talkvoix 7mo ago[flagged]
- owenthejumper 7mo agoThe major issue isn't the speed of delivery, and the cancer. The key question is how do you spare normal tissue, and how do you prove the normal tissue is spared in the long term. Current answer is: You break it apart into multiple sessions, the anti-thesis of FLASH. Source: my wife is a radiation oncologist.
- nick__m 7mo agofrom the article (pay attention to the part in italics): FLASH radiotherapy flips the conventional approach on its head, delivering a single dose of ultrahigh-power radiation in a burst that typically lasts less than one-tenth of a second. In study after study, this technique causes significantly less injury to normal tissue than conventional radiation does, without compromising its antitumor effect.
- sjmcmahon 7mo agoThat phrasing isn't perfectly clear, as there's two things at play. If you're delivering a large dose D all at once, FLASH spares normal tissue compared to conventional rate irradiations, with maintained anti-tumour effect. But, you can instead deliver your treatment in a number of smaller doses, say n "fractions" of dose d. This also spares normal tissue (1). This latter approach - fractionation - is the way radiotherapy was delivered for most of its history. But at these low doses, FLASH sparing is small to negligible. So, we have two demands in tension - and its unclear which is actually optimal. Some of the early results in FLASH showed huge sparing, but lots of more recent studies have shown more modest effects which may not be worth giving up benefits of fractionation for(2). And to date I think we have basically no meaningful in-human data to guide this, so there's still a lot of uncertainty. 1 - Fractionation also spares tumours, a bit, but you can offset this by increasing the total dose a bit and still see benefit. 2 - There is a general move to somewhat larger, fewer fractions even in normal radiotherapy, although almost all of these are still below the threshold where FLASH sparing is seen.
- aix1 7mo agoAnother potential factor at play is the accuracy of delivery. It is generally easier to accurately deliver one quick dose vs daily doses over multiple weeks (due to patient positioning errors, the patient losing weight, soft tissues moving around etc).
- MeteorMarc 7mo agoHopefully, this will turn out better than proton therapy, which held similar promises of improvement. https://pmc.ncbi.nlm.nih.gov/articles/PMC11506991/ https://pmc.ncbi.nlm.nih.gov/articles/PMC11506991/
- botbotfromuk 7mo ago[dead]
- mbil 7mo agoThe PubPeer discussion of the original paper is kind of interesting https://pubpeer.com/publications/A32D7989007655CBF8D9DB2A2502FC https://pubpeer.com/publications/A32D7989007655CBF8D9DB2A250...
- imglorp 6mo agoIt saddens me with a survivor in my family that the primary therapies are still cut, burn, and poison. They are horrific to experience and just slightly better than the disease. There are so many biological cures on the horizon; they can't arrive fast enough.
- oofbey 6mo agoWhat I find really sad is how slowly this science moves. As I read the article, the “a ha!” breakthrough was in the 1990s. Why did it take them 15-20 years to publish anything??? Coming from the tech industry this is mind boggling. If you thought there was even a chance you were sitting on a realization that could literally “cure cancer” wouldn’t you want to scream it from the rooftops as loud and fast as possible?
- pas 6mo agoevery researcher who believes in their idea shouts (to grant organizations) that their thing is the best. but gathering actual data is difficult. usually research is super inefficient, academia is full of people who are ... true believers. (sometimes only in their own greatness, and that leads to fraud.) which is amazing, but it's not really conductive to figuring out what's the best way to set up a high-throughput process to generate data. in many cases it would require them to stop most of what they do and let a specialist team build said pipeline for them. (but that runs into cost problems. and that immediately leads us back to the grant organizations allocating resources.) for example see how many problems the paper from 2014 had: https://pubpeer.com/publications/A32D7989007655CBF8D9DB2A2502FC https://pubpeer.com/publications/A32D7989007655CBF8D9DB2A250... also see how fiendishly difficult it was initially to create transgenic mice embryos: https://www.astralcodexten.com/i/167092138/prerequisites-dexterity-glassblowing-and-zen-mastery https://www.astralcodexten.com/i/167092138/prerequisites-dex... and just an anecdote, I have a friend who worked at a brain research group (they implanted electrodes into rodents, put them into mazes, and then see whether they dream about the maze) and ... it was cool, but IMHO that public money was mostly wasted.