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One whole-body MRI could replace multiple cancer scans

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Re: One whole-body MRI could replace multiple cancer scans

#171

Post by Brakenshire »

louden wrote: post #167
Brakenshire wrote: post #165

Earlier quoted context omitted.

It’s perfectly reasonable not to use such a test if medical science doesn’t have strong evidence what the data means. Likely that sort of statistical evidence would require institutions with teams of researchers managing and adjusting screening campaigns rather than the judgement of an individual doctor anyway. I really can’t accept the idea though that any test which is safe, cost and time effective, and produces ac…

You are comparing a program where the benefits vastly outweigh the cost to a program where the benefit is mostly speculative and the cost known. The cost of full body imaging is not just in the scan itself but in the procedures that follow it that require anasthesia (non-zero chance of killing the patient), cause pain and may cause secondary infection. In fact, just being in the hospital or doctors office to get the…

I agree in the sense that this appears to be the reality of the situation at the moment, that the benefit is speculative because of a lack of evidence for the effectiveness of either the data or our ability to interpret it. I highly doubt that will be the case in the long run, as costs come down, resolution goes up, and analysis software improves.

Re: One whole-body MRI could replace multiple cancer scans

#172

Post by mattkrause »

Wowfunhappy wrote: post #160
mattkrause wrote: post #112

Earlier quoted context omitted.

You're understating the costs. Determining whether something is (non) malignant isn't trivial. It often requires a more invasive test (e.g., biopsy, exploratory surgery). We try to avoid those procedures not just because we're cheap or afraid, but because they have a real risk of harming us 'squishy humans'. For example, detecting prostate cancer a few months earlier is often not a huge win on its own. It is even les…

> For example, detecting prostate cancer a few months earlier is often not a huge win on its own. It is even less of a success if doing so requires that four people have allergic reactions to the anesthetic and two others acquire some kind of infection at the biopsy site. Then the doctor should recommend not attempting that type of detection. I find it quite hard to believe that, in an ideal world (!), less data woul…

Sure, in the not-for-profit Vulcan medical system, this would might be grand. Even in our world I'd agree that in isolation, more information is always better.

The issue is that this sort of information isn't free. The full body scan isn't free. Following up on it, which is the whole point, 'costs' increased risks of adverse outcomes (from biopsies), it 'costs' emotional anxiety, and it costs even more actual money.

The argument is that right now, these whole body scans aren't worth the cost. You're more likely to find a few things you should ignore (but will probably worry over) and a few things you should follow up on (but will be benign). You're less likely to catch something deadly and just in the nick of time.

Re: One whole-body MRI could replace multiple cancer scans

#173

Post by mattkrause »

Someone wrote: post #163
mattkrause wrote: post #112

Earlier quoted context omitted.

You're understating the costs. Determining whether something is (non) malignant isn't trivial. It often requires a more invasive test (e.g., biopsy, exploratory surgery). We try to avoid those procedures not just because we're cheap or afraid, but because they have a real risk of harming us 'squishy humans'. For example, detecting prostate cancer a few months earlier is often not a huge win on its own. It is even les…

”Determining whether something is (non) malignant isn't trivial. It often requires a more invasive test (e.g., biopsy, exploratory surgery)” Not necessarily, waiting can in many cases tell you whether something is malignant. If we had, say, a century of monthly full-body MRIs of a million persons, together with their history and cause of death, the technology to align those scans across time, and the technology to an…

Two reasons I think this is not the way to go:

First, the cost would be insane. A century of monthly MRIs is 1200 scans per person, or 1.2B scans to finish your hypothetical dataset. We pay about $US 550/hr for scanner time, using a research scanner that's subsidized (i.e., we're just covering costs, not making a profit). The article doesn't say how long the scan is. You can burn as much scanner time as you want chasing resolution/quality, but an hour seems reasonable. That comes out to $660B, which is...a lot, and we haven't even paid staff yet!

Second, we have sorta tried this already. There's a massive neuroscience project to scan tons of brains called the Human Connectome Project. They have 1200 subjects, some scanned multiple times, behavioral measures, health outcomes, the works....

People have certainly found stuff in the data (I'm using some of it right now), but it hasn't lead to wild breakthroughs. There's a ongoing debate about whether this money would have been better spent on hypothesis-driven research instead.

Re: One whole-body MRI could replace multiple cancer scans

#174

Post by mattkrause »

copperx wrote: post #125
mattkrause wrote: post #104

Earlier quoted context omitted.

Nope. Really, it's a question of priorities. Scanners cost a lot: ~4M for a 3T (the current 'standard') and much more for higher field strengths. We just got a 7T and, with all the trimmings (scanner, console, coils, the shielded room to hold it all, training, etc), it's in the $10-15M range. As a result, time on these things is already in pretty high demand, even at facilities that are used only for research. The pr…

> We just got a 7T Where is that? Might be worth the trip in some cases.

I'm in Montreal, but 7Ts are popping up all over, especially now that Siemen's Magnetom Terra got FDA approval.

I know Yale also has a 7T, as does the NIH, Stanford, and MGH (I think--it's somewhere in Boston). The University of Minnesota has THREE which is crazy.

Re: One whole-body MRI could replace multiple cancer scans

#175

Post by tellak »

WoodenChair wrote: post #158
tomcam wrote: post #155

Earlier quoted context omitted.

> The start of your post feels like "appeal to authority." Sounds like a declaration of fact to me

What I mean is, just because the person is "actually an MD" doesn't mean the person has expertise in this specific area yet the person is using it to claim such. I.E. some might call me a computer scientist, but that doesn't mean I have enough expertise in machine learning, a sub-discipline, to say definitively that the OP's idea about using full body scan data is feasible. Should I have started my post "I am actuall…

It’s not a big deal. I only mentioned as a response because the op started off saying they were from a family of MDs.

Also the vast majority of practicing physicians are expected to have detailed expertise to understand the indications, application, and interpretation of imaging within their speciality. Most imaging orders are issued by medical or surgical staff, not radiologists.

Re: One whole-body MRI could replace multiple cancer scans

#176

Post by abecedarius »

MegaButts wrote: post #161
abecedarius wrote: post #138

Earlier quoted context omitted.

Yup, agreed! In fact I wouldn't have done the test mentioned above if I'd been better informed (an MRI with gadolinium contrast; I was only told the latter bit the day I showed up for it. There seems to be a bit of controversy about possible low-level health effects of this contrast agent, and considering I was very probably fine a priori, I think it was a mistake to do this. But it's kind of another thing to decide…

My hunch from reading these comments is that the doctors tend to be experienced and pragmatic, and their experience teaches them what tests matter and when. The problem with this though is they start to believe those tests are useless when they might not be. It becomes more complicated when you consider doctors have limited time and resources and cannot spend too much time with any single patient, at least the way th…

Sympathies -- I've had some experience of that sort too. I'd have more sympathy with the doctors' side (it is a very difficult position) if they weren't set up as gatekeepers.

Re: One whole-body MRI could replace multiple cancer scans

#177

Post by mattkrause »

chris_va wrote: post #14
sampleinajar wrote: post #4

> The average cost of a WB-MRI scan for NSCLC patients was £317 Wow! $3000+ here in the US. Ever get the feeling you've been cheated?

Not all MRI machines are equal, though, so it's hard to tell without specifics. A low field 0.2T machine might be $150k. A full bells+whistles 3T machine might be $3M.

The 'bells and whistles' model is starting to move to 7T, and the price scales accordingly.

Re: One whole-body MRI could replace multiple cancer scans

#178

Post by mattkrause »

toomuchtodo wrote: post #3
eutropia wrote: post #2

With sufficient software and computational horsepower, a single whole-body MRI could replace most diagnostic imaging systems, I'd wager. Computer models regularly outperform radiologists in diagnosing several conditions involving structural abnormalities.

On to driving down the cost of MRIs and eliminating their need for helium.

Phillips and GE both have new models that use a lot less (10-20L vs. 1000L) of helium. I think they're only 1.5T though.

The Phillips model is called "BlueSeal"; I can't remember GE's, but it's something goofy.

Re: One whole-body MRI could replace multiple cancer scans

#179

Post by mattkrause »

eutropia wrote: post #2

With sufficient software and computational horsepower, a single whole-body MRI could replace most diagnostic imaging systems, I'd wager. Computer models regularly outperform radiologists in diagnosing several conditions involving structural abnormalities.

Gonna have a hard time with bones....

Re: One whole-body MRI could replace multiple cancer scans

#180

Post by Flemlord »

nknealk wrote: post #13

Many doctors hate full body scans. Every individual has a handful of anomalies which are almost always benign. They show up on full body scans and chasing them down comes with cost and patient risk. I have a hard time with reporting like this that doesn't quantify cost of biopsy on false-positives as well as cost of complications from examining false-positives. Source: worked in clinical research for 2 years.

Wouldn't you compare back to an original/baseline scan, making it easy to ignore anomalies?
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