It's a controversial and complicated idea. The downside, and the reason why most doctors do not recommend full body scans, is that every human body is a bit weird and there will almost always be something "wrong" that will be visible in a full body scan. This can lead to unnecessary testing, anxiety, and even unnecessary procedures. Many of these oddities flagged by the scan would never have caused any actual issues had the patient never been aware.

While there are many individual stories of full-body scans detecting early-stage cancer before it became symptomatic, there seems to be a general sense among doctors that implementing full-body scanning on a population level would lead to overall more harm than good. The thinking is that it is better to do regular targeted screenings for diseases that you're in a risk group for (e.g. colonoscopies, mammograms, cancer marker blood tests, etc.) rather than full-body scans.

I'm not a doctor, and I personally do find the idea of full-body scans very appealing, but I also know that if the scan detects a possible cancer, I wouldn't be able to just ignore it if the doctor tells me it's likely ok. Any time I felt any pain or any sort of symptom in that general area, I know I would worry about it. Maybe that's worth it for the potential life-saving results, but it definitely is a cost of this type of scan that needs to be acknowledged.

Exactly - I had switched to a one meal per day setup and have been mostly following it for a few years.

Then after a routine “heart health” check all my indicators were super out of whack - the doctors thought I was on my deathbed - but I am perfectly happy pain free, in shape, physically active person…

Then _i myself_ had to dig into all these tests and figure out that they were measuring the wrong thing - since they try to time where your body is “just about to eat after a fast” - normally for most people in the morning before breakfast, but since my first meal of the day is usually around 20:00 - my body had adopted to have higher levels of various things just to stay on top of my lifestyle choices.

Anyway I had to educate some doctors since they haven’t really had a case like mine, so they weren’t thinking critically of how to interpret the results…

I imagine an automated test _could_ take these things into account with large enough dataset, but it would need to do a lot more reasoning than statistical correlation.

I do believe current sota models should be good enough to come to the correct conclusions with the right harness though.

If the whole population had a full body scan every quarter, the “weird” things would feel more like the noise they are.

But we would have great data over time, both individually (weird tends to only matter if they are changing) and as a population.

All doctors say this, and that sort of drove me away from healthtech. As if there were absolutely no way to take a step in a direction of fixing it.

The faster and earlier we start to scan everyone regularly, as long as scanning methods aren't invasive, the more certainty we'll have what to warn people about and what not to tell them. Perhaps with the regular screening (imaging quarterly, if the scan is fast) you could see what is growing and what isn't.

> every human body is a bit weird and there will almost always be something "wrong" that will be visible in a full body scan

Would this be solved by routine scans, so you have a baseline you can compare against? Ignore anything slightly odd in the first scan but monitor for changes over time?

The question is: If you have enough full body scans of many healthy people, and the statistical tools to model it (beyond "this range is OK"), whether this would reduce these false alarms to an acceptable level.

The real crux of it remains though: Let's say it finds something that increases your death risk by x=0.1%. Could you sleep? I'm not sure. Let's say the operation has 2x=0.2% risk. What do you do? What value of x makes this a problem for you?

One obvious alternative plan, presupposing that Full Body Scan is dirt cheap, is the following protocol:

- At 25 years old or whatever you get a FBS. Pretty much no matter what, this FBS will not be used to do more checks, procedures, and so on.

- ... and now we give you another FBS every so-many years, and only those things that are different from the previous scan are investigated.

There's still an issue with needless procedures, but the amount of 'weirdness that are not going to cause an actual issue had the patient never been aware' is significantly reduced by looking only at changes. i.e. most 'weirdness' shows up early and is fairly stable.

The difficulty is the moral issue. You cannot show that first scan to the patient. Even if every soul agrees beforehand that the rule is that nothing on that first scan, no matter how scary it looks, is further investigated... any medical issues raised by patients are used as a major information input for diagnosing issues. If I show a patient a scan that has this tumor looking thing on the left lung, then no doubt a few months later they'll be back complaining about shortness of breath and a pain on the left side of the torso. The mind is a powerful thing. At that point you can do a scan and see... the same nasty tumor looking thing we saw on that first FSB, and we're right back to the issue of these scans doing more harm than good.

Is it morally acceptable to hide that first scan from the patient?

I think the anodyne to this is - and I admit the degree to which this is indicative of my biases! - more data, especially early on. Getting a good baseline before you have really any significant chance of most cancers to be able to do within-individual diffs, effectively, might be a big deal.

It might also reveal that every MRI shows ghost artifacts a half a dozen times that make it longitudinally useless, of course. I'm not foolish enough to think that epidemiologists haven't thought of this.

"It's a controversial and complicated idea. "

It is neither controversial nor complicated to detect some cancers by scent.

Taking the "headspace" of something is also not really complicated.

There are people who can reliably smell/detect Parkinson:

https://www.npr.org/sections/health-shots/2020/03/23/8202745...

You're absolutely right, and I share the frustration.

I'm thinking a possible solution to this signal-to-noise problem is to embrace the longitudinal view: instead of comparing each scan with the normal across the population compare only against past self, unless there's a risk factor that warrants it.

This way we could presumably make use of plentiful scan data and mostly look at the stuff that evolves in suspicious ways, not what looks suspicious.

This always feels like a thinly veiled excuse to ration healthcare. Would these same doctors refuse a full body MRI to a billionaire paying out of pocket?

Anything found can be monitored with focused follow up scans. It doesn't have to be immediately biopsied if it's in a location where that would pose a risk of iatrogenic harm.

All the reasons you’ve listed are excuses why my government healthcare stopped having annual checkups. But to me it’s just worse quality care

I've heard this argument before and it's always seemed downstream of capacity constraints and the current incentives of the healthcare industry.

There's a reason why billionaires like David Rockefeller, Larry Ellison, and Rupert Murdoch are able to live much longer lives than average, and having an oncall health team (that I'm sure does frequent testing and monitoring) is a big contributor to that.

More testing and data collection doesn't mean that every single anomaly would need to be investigated or communicated with the patient, but would provide a better longitudinal view that can help with disease prevention and health optimization.

>> It's a controversial and complicated idea

sure, and there will be downsides.

But that data will be valuable nonetheless.

Sorry, but that's a morally corrupt idea.

[dead]