Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

One whole-body MRI could replace multiple cancer scans

pharmatimes.com

Post reply on HN
Print view View original

111–120 of 236 posts

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

#111

Post by jedberg »

I've had this idea floating in my head for a while. Provide free annual full body MRIs to people, including being read by a radiologist, which they can take to anyone they want (doctor, lawyer, whatever). In exchange, they agree to send the org a copy of all their past and future medical records. The records are anonymized and tied to the MRIs.

The MRIs and medical data is then pumped through machine learning algorithms to attempt to identify early signs of disease. The data of course would be most useful to future people, because we won't know someone has something until a doctor diagnoses it, but if the AI model can look at the MRI from five years ago on everyone with disease X and find a common early warning sign, then we could apply it to future cases where it might be possible someone has X and catch X much earlier.

Basically, I want to create a charity that gives free full body MRIs in exchange for a bunch of medical data for training an AI.

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

#112

Post by mattkrause »

rolleiflex wrote: post #67
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.

A decent portion of my family are MDs. This is accurate. However, this is also one of the places where it's quite disappointing to see human squishiness in action. When we opt to not receive data because we know there'll likely be non-malignant anomalies, we are also depriving ourselves of the raw data that allows us to discern non-malignant from malignant, data which would help very much in deciding on the cases we…

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 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.

It's certainly possible that more data would eventually let us avoid most invasive followups, that's nowhere near certain. Even if it were, the ethical calculus is still pretty tricky.

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

#113

Post by jedberg »

a11r wrote: post #70
whatshisface wrote: post #35

Earlier quoted context omitted.

Why can't a doctor see an anomaly and decide not to chase it down based on the same reasoning that they use to not scan for it? Is there some pointless legal trap related to malpractice where the only allowable "don't operate" decision happens when the doctor decides what to test for?

Most tests are probabilistic and you have to think about the conditional probability given other indicators. Consider a urine culture for detecting UTIs. If you just get urine samples from a general population, some fraction will show positive (bacteria in the culture) falsely. It would be pointless to perform this test on the general population and to treat people that show positive . But if you perform this test co…

But why can't they go the other way? Oh, you had bacteria in your urine, do you feel a burning or have a fever? You'd have to find a way to ask that doesn't incite a false response, but it still seems like it would be useful.

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

#114

Post by mattkrause »

abecedarius wrote: post #101
arkades wrote: post #76

Earlier quoted context omitted.

Well, that’s part of why there’s constant research into what risk factors / predictive factors are. These aren’t mutually exclusive activities. “Data” implies something neutral. Nothing about lab tests is neutral. Without contextual information and studies on how to -interpret- a finding, it’s just potentially terrifying noise. And terror usually results in action. Poorly informed action is often harmful. So... we ar…

For a rational agent the expected value of information is never negative. (Of course it can be less than the cost of the test.) If a system is treating it as negative, that's a problem to fix. I'm reminded of a recent visit to a doctor who refused to say anything quantitative about a test. Sure, your average client knows little decision theory, but this doctor either didn't either or pretended not to follow. To make…

We could do an autopsy on you right now if you want. How sure are you that you just stubbed your toe and it's not some highly metastasized cancer?

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

#115

Post by nnq »

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.

MDs are idiots in this regard. Mainly because they've been thought medicine by other idiots. They have this stupid idea that "too much data" is bad, also stuff being a sign that you're a bad doctor if you order too much tests etc. It's a whole can of worms of crappy rationalizations here, that also hides the fact that doctors are not capable or trained to correctly deal with large volumes of data, so they know they will make mistakes that they will be liable for if they are handed more data!

More data is always better. Period.

Problem is that we lack some kind of protocols of "calculated ignorance" that they could follow, like be allowed to ignore large classes of semi-normal findings that would show up often and lead people on wild goose chases, and be safe from malpractices and stuff if they follow this "calculated ignorance". This is because in the end medicine is not about doing "the best thing at all cost", but at doing the best thing that can be done at population scales, under limits of financial cost and "comfort cost" (there are limits after most of us would prefer (high risk of) death instead of further investigations and treatments and these limits vary (wildly) by individual).

There's two things that should be drilled down into the heads of all domain experts: (1) more data is always better, and (2) it's ok to ignore as much of the data as you want if it doesn't make sense cost-wise to investigate it further. But it's always better to fish in a larger lake!

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

#116

Post by needlesurgeon »

rolleiflex wrote: post #67
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.

A decent portion of my family are MDs. This is accurate. However, this is also one of the places where it's quite disappointing to see human squishiness in action. When we opt to not receive data because we know there'll likely be non-malignant anomalies, we are also depriving ourselves of the raw data that allows us to discern non-malignant from malignant, data which would help very much in deciding on the cases we…

For those interested, I have posted a relevant screening-exam paper on the main thread that asks the question, "what do we find if we scan the brains of 2000 people?":

https://news.ycombinator.com/item?id=19965095

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

#117

Post by abecedarius »

arkades wrote: post #109
abecedarius wrote: post #101

Earlier quoted context omitted.

For a rational agent the expected value of information is never negative. (Of course it can be less than the cost of the test.) If a system is treating it as negative, that's a problem to fix. I'm reminded of a recent visit to a doctor who refused to say anything quantitative about a test. Sure, your average client knows little decision theory, but this doctor either didn't either or pretended not to follow. To make…

Cool, so your serum zorblaxian levels are 300 ng/L. The finding was incidental, so it’s jot tied to existing symptoms / clinical suspicion. It’s a molecule involved in the inflammatory cascade. We don’t know what diseases it’s associated with or not, nor what the change in probability of having the diseases it could be associated with are, not change in prognosis. But, you have a number which your local lab pegs at 1…

Framing it as a choice between "have a cookbook decision tree that's been validated by RCTs in exactly this context" and "do a lot of costly (in resources and side effects) followup tests to show we're doing everything we can" is an example of the irrationality that needs fixing. People are capable of actually reasoning with uncertainty when they care about outcomes. When it's you, personally, facing a decision in your life, you don't throw up your hands and say "It's too complicated to decide! There are no actuarial tables about exactly this situation!" Having to decide means having to make a bet. You can be a better or a worse gambler, but we're all gamblers. Medicine as a profession seems to want to pretend they're not, rather like "investors" pretend to be qualitatively different from "speculators".

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

#118

Post by louden »

nnq wrote: post #115
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.

MDs are idiots in this regard. Mainly because they've been thought medicine by other idiots. They have this stupid idea that "too much data" is bad, also stuff being a sign that you're a bad doctor if you order too much tests etc. It's a whole can of worms of crappy rationalizations here, that also hides the fact that doctors are not capable or trained to correctly deal with large volumes of data, so they know they w…

More data is not always better. The collection process itself can be dangerous or unpleasant for the patient.

Several years ago I worked on a study looking at the spread of bacterial lung infections in long term hospital patient. In order to get the data, we would have to intubate patients that did not need it. In this case, the people who approve these studies rightfully ruled that getting that data would be too painful for the patients to allow.

Biopsies caused by benign findings from a full body scan are not without pain, emotional distress, risk or cost to the patient. Period. It must be weighed against the benefit that the patient would recieve (all in the aggregate, or course).

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

#119

Post by ska »

whatshisface wrote: post #35
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.

Why can't a doctor see an anomaly and decide not to chase it down based on the same reasoning that they use to not scan for it? Is there some pointless legal trap related to malpractice where the only allowable "don't operate" decision happens when the doctor decides what to test for?

   Why can't a doctor see an anomaly and decide not to chase it down based on the same reasoning that they use to not scan for it?
In the US at least, one answer is malpractice litigation.

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

#120

Post by arkades »

abecedarius wrote: post #117
arkades wrote: post #109

Earlier quoted context omitted.

Cool, so your serum zorblaxian levels are 300 ng/L. The finding was incidental, so it’s jot tied to existing symptoms / clinical suspicion. It’s a molecule involved in the inflammatory cascade. We don’t know what diseases it’s associated with or not, nor what the change in probability of having the diseases it could be associated with are, not change in prognosis. But, you have a number which your local lab pegs at 1…

Framing it as a choice between "have a cookbook decision tree that's been validated by RCTs in exactly this context" and "do a lot of costly (in resources and side effects) followup tests to show we're doing everything we can" is an example of the irrationality that needs fixing. People are capable of actually reasoning with uncertainty when they care about outcomes. When it's you, personally, facing a decision in yo…

It’s not “cookbook decision tree”, it’s “data from which to make meaningful inferences about this finding.” It would be nice if we always have that; with incidental findings, we often don’t.
Post reply on HN