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CT Scan "Reset Error" Gives 206 Patients Radiation Overdose

Soulskill posted more than 4 years ago | from the paging-dr-simpson dept.

Medicine 383

jeffb (2.718) writes "As the LA Times reports, 206 patients receiving CT scans at Cedar Sinai hospital received up to eight times the X-ray exposure doctors intended. (The FDA alert gives details about the doses involved.) A misunderstanding over an 'embedded default setting' appears to have led to the error, which occurred when the hospital 'began using a new protocol for a specialized type of scan used to diagnose strokes. Doctors believed it would provide them more useful data to analyze disruptions in the flow of blood to brain tissue.' Human-computer interaction classes from the late 1980s onward have pounded home the lesson of the Therac-25, the usability issues of which led to multiple deaths. Will we ever learn enough to make these errors truly uncommittable?"

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383 comments

Will errors ever go away? (4, Insightful)

s73v3r (963317) | more than 4 years ago | (#29746441)

As long as people are involved in some way, no.

Re:Will errors ever go away? (-1, Troll)

Anonymous Coward | more than 4 years ago | (#29746463)

Eat a niggerdick [goatse.fr] . Everyone else does.

Re:Will errors ever go away? (3, Insightful)

courteaudotbiz (1191083) | more than 4 years ago | (#29746559)

Mmmmm, anyway, people are always involved if you have a machine. The machine didn't build itself!

Re:Will errors ever go away? (4, Funny)

argent (18001) | more than 4 years ago | (#29746689)

The machine didn't build itself!

SPEAK FOR YOURSELF, MEATSACK!

Re:Will errors ever go away? (4, Funny)

Arthur Grumbine (1086397) | more than 4 years ago | (#29747229)

The machine didn't build itself!

SPEAK FOR YOURSELF, MEATSACK!

Oh, yeah?! Well who built your first model, you bucket o' bolts! And don't give me that FSM nonsense. Everyone knows that the Fantastical Spawning Machine was truly the work of humans, inspired by the intelligently designed schematics given to us by the noodley appendage of the true FSM.

Re:Will errors ever go away? (4, Funny)

FatdogHaiku (978357) | more than 4 years ago | (#29747349)

SPEAK FOR YOURSELF, MEATSACK!

Scanning with high intensity radiation reveals he is in fact about 60 percent water, 16 percent protein, 15 percent fat, and about 3 percent nitrogen... So, more of a stringy, greasy, slightly gassy water bag really.

Sorry about the high levels of radiation used to obtain the data, your armpits should stop smoking any minute now.

Re:Will errors ever go away? (0)

Anonymous Coward | more than 4 years ago | (#29747109)

Why isn't there a sensor in the machine that detects the level of radiation being emitted? Shouldn't it have an alarm if the sensor is A) gone/bad or B) higher than X (where X is non-lethal, but still more than you'd ever need). At least this way only ONE person would get the lethal dose!

It's About Automation (5, Insightful)

Alaren (682568) | more than 4 years ago | (#29746893)

This is probably modded insightful because we're all familiar with "human error," but it misses the point of the article (and is sort of misanthropic, too).

This particular error is the kind that occurs when you simplify complex procedures in the interest of widespread use. It is the fault of specialization, which we typically embrace because it allows us to leverage human labor into increasingly complex areas of inquiry. It's more than just "human oversight" or "machine failure," it's the kind of problem that typically arises when people are trained to use machines without being trained to fully understand those machines.

A certain segment of society--that's mostly us geeks--strives against this tendency; we become technicians in various fields. But most people, including medical people, get trained by vendors to use a particular piece of software or hardware without reference to its underlying principles or inner workings. This is normal and usually beneficial for various reasons an economist could doubtless relate.

The sad reality is that, so long as it doesn't kill too many people, any innovation that leads to greater economic efficiency will be accepted and embraced. The obvious example is automobiles, which (even adjusting for factors like alcohol) kill a startlingly large number of people. Those deaths are mourned, but ultimately absorbed by the human race as the cost of doing business. This makes some people resent automation, resent technology, et cetera... but most of us find other ways to cope.

Re:It's About Automation (-1)

Anonymous Coward | more than 4 years ago | (#29747039)

I don't think being trained to fully understand the automobile will decrease the number of automobile related deaths.

"From that knocking sound, I think my engine may . I'm so glad I got all this training, so I won't get into any car accide... ***SCREECHING TIRES*** ***LOUD CRASH***

Re:It's About Automation (5, Insightful)

antifoidulus (807088) | more than 4 years ago | (#29747049)

The advantages of simplified training are not just beneficial on an economic scale. While its unfortunate that this error killed people, think of how many more people would die if complex training was required to use these types of machines. Ultimately, it would lead to fewer operators and thus less access to the machine, which ostensibly helps save lives.

Re:Will errors ever go away? (1)

thePowerOfGrayskull (905905) | more than 4 years ago | (#29747235)

As long as people are involved in some way, no.

Indeed. The problem here is that whenever you have to communicate something, there's no way to be 100% sure that 100% of your users will see what you intended, in the way that you intended it. You can explain everything perfectly clearly and concisely - but because humans don't read minds, all words and visual cues are subject to interpretation by indviduals.

Not the engineers fault (5, Funny)

PhasmatisApparatus (1086395) | more than 4 years ago | (#29746447)

Requiring that doctors RTFM is the first step.

Re:Not the engineers fault (5, Insightful)

betterunixthanunix (980855) | more than 4 years ago | (#29746493)

The machine's software should not be capable of triggering the release of that much radiation; any change in the radiation levels should require some kind of hardware interaction. Even an idiot who did not RTFM should not be able to cause harm with the machine.

Re:Not the engineers fault (4, Insightful)

vertinox (846076) | more than 4 years ago | (#29746627)

The machine's software should not be capable of triggering the release of that much radiation; any change in the radiation levels should require some kind of hardware interaction. Even an idiot who did not RTFM should not be able to cause harm with the machine.

I'm not sure what you mean by this? Most hardware is software these days.

Or are you talking about having a red button with a safety lock on it that has to be pushed in order to work?

Either way, people still bypass hardware solutions.

Re:Not the engineers fault (4, Insightful)

Serenissima (1210562) | more than 4 years ago | (#29746761)

I think he means it should be hardwired into the unit to NEVER EVER exceed a certain level of X-Ray radiation. That should be the default. If there's some medical reason why the dosage needs to increase, you should have to turn it UP to that dosage and then the machine should reset itself to the default. There should NEVER be a problem of the machine defaulting to an extremely high level of radiation requiring personnel to turn it down. It should always start out low in case some dumbass technician runs the machine without making any changes.

Re:Not the engineers fault (4, Insightful)

Sockatume (732728) | more than 4 years ago | (#29747043)

Don't even hard-wire it. Engineer it so that operating in the high-dose regime requires physical intervention, a "Kill Handle" with a lock and key. The machine should be physically incapable of generating an above-standard dose when the "Kill Handle" is not being held. Limit the power, or something. (The aformentioned Therac incident happened, in part, because such a hardware interlock did not exist.)

Re:Not the engineers fault (0)

Anonymous Coward | more than 4 years ago | (#29747153)

Why not have two keys which are impossible to turn by a single person, like in nuke launch facilities?

Re:Not the engineers fault (0)

Anonymous Coward | more than 4 years ago | (#29747327)

what is worse is that Therac-20 HAD the interlock, but the 25 no longer had the interlock installed. That's why the 20 worked fine and one of the reasons why the 25 had the capability to overdose.

Re:Not the engineers fault (0)

Anonymous Coward | more than 4 years ago | (#29746997)

"Warning: This machine is set to give a dose *eight* times the recommended dose for this treatment. To proceed, press Green."

Doesn't stop eight time the recommended dose being given, but it should stop all trained operators.

Definite UI issue with the basic design of the machine, in my opinion.

Re:Not the engineers fault (1)

jscalbny (1252620) | more than 4 years ago | (#29747053)

I suspect they were imagining some sort of firmware lockout cap for the radiation dosage. Still technically software, but not something readily modified by the end-user to bypass safety tolerances.

Sounds like the doctors didn't anticipate the machine's implementation of the new scan's program, but a firmware safety more likely might have caught the production of overdose range radiation amounts?

Re:Not the engineers fault (1)

betterunixthanunix (980855) | more than 4 years ago | (#29747139)

"Most hardware is software these days."

Therein lies the problem. There should be a hardware mechanism that limits the maximum power the machine can operate at, despite what the software requests. If there is a reason to increase that limit, it should have to be done in hardware, using a mechanism that automatically resets after a single run. The process of overriding the hardware limit should be conspicuous: nobody should be able to do it without intending to do so. Preferably, it should be obvious when the limit has been overridden (e.g. something should be very different from normal when you use the machine), to prevent a doctor from activating a machine that has a raised power limit without realizing it (e.g. if a technician raises the limit then walks away).

These are not Earth-shattering concepts. These ideas fall more under the category of "basic safety." Software is too fragile, and software switches are too non-obvious, to be relied upon to manage these things.

Re:Not the engineers fault (1)

DRAGONWEEZEL (125809) | more than 4 years ago | (#29746633)

/agree. Was just going over this w/ someone in the field. It's amazing that it happened in the first place, more amazing that almost 200 patients went by before this was caught. If that happened at a larger hospital it SHOULD have been in the thousands.

Re:Not the engineers fault (4, Insightful)

snowraver1 (1052510) | more than 4 years ago | (#29746639)

Hardware interaction... Like maybe "[...]resetting the machine to override the pre-programmed instructions that came with the scanner when it was installed."?

I'm willing to bet that the person that modified the machine has read, at least, the relevant parts of the manual.

Re:Not the engineers fault (5, Insightful)

Greyfox (87712) | more than 4 years ago | (#29747111)

My machine would irradiate the operators by default and would require that a obscure button sequence be pushed in order to irradiate the patient instead. That way the idiot who didn't RTFM would end up dying of radiation poisoning, not the patient. Eventually the survivors who DID RTFM would breed and pass on their proclivity to RTFM. Really it's for the good of the entire human race, if you think about it...

Re:Not the engineers fault (5, Insightful)

smitty777 (1612557) | more than 4 years ago | (#29746587)

Couldn't disagree more. Unfortunately, enforcing training and reading manuals would probably have little effect. In my 10+ years doing usability for missile systems, you have to build in the mechanisms to keep the users from doing bad things. Even if you force the user to read the *entire manual* before each use, people still have bad days, hangovers, fights with significant others. It has to be designed in.

Re:Not the engineers fault (2, Interesting)

NonSequor (230139) | more than 4 years ago | (#29746807)

Couldn't disagree more. Unfortunately, enforcing training and reading manuals would probably have little effect. In my 10+ years doing usability for missile systems, you have to build in the mechanisms to keep the users from doing bad things. Even if you force the user to read the *entire manual* before each use, people still have bad days, hangovers, fights with significant others. It has to be designed in.

The story behind Murphy's Law [wikipedia.org] is pretty interesting and it ties in with this design philosophy.

Basically the story is that a technician incorrectly installed force sensors and in response, Murphy got pissed off and said "If that guy has any way of making a mistake, he will."

However, other people adapted that statement into "If anything can go wrong, it will," expressing the idea that if a system does not mechanically exclude the possibility of human error, human error can be expected to occur. This makes accounting for human error a design constraint.

Re:Not the engineers fault (1)

Demonantis (1340557) | more than 4 years ago | (#29746763)

"You have to be pretty confident to think you know more than the guys who designed the equipment."

I think it speaks volumes. I don't think they would RTFM even if you threatened them it would be a conflict of their personality.

Re:Not the engineers fault (1)

Slipped_Disk (532132) | more than 4 years ago | (#29746805)

Being in the medical field these days (though not in the nuclear medicine area) I can say that doctors are even less likely than CS geeks to RTFM. It is always the engineer's responsibility to take all reasonable steps to ensure that a system can not cause harm to patients, doctors or technicians, even if used improperly.

The fact that nuclear medicine equipment continues to ship without an absolutely paranoid level of hardware safety interlocks 20+ years after the Therac-25 incidents is appalling.

Re:Not the engineers fault (1)

nomadic (141991) | more than 4 years ago | (#29746863)

Because this is slashdot, where it's NEVER the engineer's fault...

Default setting... (5, Insightful)

courteaudotbiz (1191083) | more than 4 years ago | (#29746475)

The default setting for an equipment that can be lethal should be "Emit zero radiation". Then for each exposure, set the level of radiation you intend to use. This way, you ALWAYS KNOW the level of radiation the equipment will emit.

Better investigate "Hey, we got no picture" than "Hey, we got pictures, but everyone dies after that..."

Didn't RTFA.

Re:Default setting... (4, Funny)

eln (21727) | more than 4 years ago | (#29746551)

That's really not fair...you have no idea that people would die from that radiation. It's at least equally likely they would develop super powers, join up with others who have received similar doses of radiation, and form a crime fighting team of mutants.

All I'm saying here is we shouldn't just dismiss this as a bad thing until we've fully explored the legislative and societal implications a team of crime-fighting mutants with superpowers would have.

Re:Default setting... (1)

Sebilrazen (870600) | more than 4 years ago | (#29746603)

They wouldn't really be mutants, maybe amazing, fantastic or incredible, but not mutants.

Re:Default setting... (1)

eleuthero (812560) | more than 4 years ago | (#29746741)

I want to see your remarks as funny--I do. And if I hadn't read the article already (*gasp* I may lose my account now), I probably would, but it would seem that the current problem in conjunction with historical issues with scanning devices make it a rather serious and dark matter for me. There should be hardware locks against overusing the machine. It should have a zero default setting and it should be impossible in the hardware to make the thing go beyond the normal tolerance for an adult with cancer (other invasive issue) and / or a healthy adult (whichever might have the higher tolerance since I would assume healthy people are sometimes scanned to check for cancer and they probably also have the higher tolerance). There is no reason that a normal x-ray machine should be designed to be usable as a fixed in place death ray unless we actually start passing them out to the army for that purpose (though given how slow mid-level radiation poisoning can be, it seems reasonable we have never actually gotten around to using it for more than medicine).

I think they need in-line radiation sensors (0)

Anonymous Coward | more than 4 years ago | (#29746589)

The best way to know what the equipment will emit is to test what the machine actually emits.

They need to have some sort of sensor in-line with the radiation stream to audit the hardware and software output and confirm the human configurations are in line with expectations.

I don't know the technicals and how they might impact the actual treatment, but these things are too important to rely on some expectation based on some model with nothing that is actually measured at the point of delivery.

Re:I think they need in-line radiation sensors (1)

schon (31600) | more than 4 years ago | (#29746737)

They need to have some sort of sensor in-line with the radiation stream to audit the hardware and software output and confirm the human configurations are in line with expectations.

And what if it breaks between the "what is it emitting?" stage and the "OK, point it at the patient" stage?

If it breaks, it should emit zero.

Re:Default setting... (1, Informative)

Anonymous Coward | more than 4 years ago | (#29746847)

As a user of GE machines I would have to say they are pretty well locked down. It's hard to change anything. That may sound good, but in practice it means if you *do* want to change something then you need to do some pretty nasty workarounds. E.g. you have to edit a text file on the scanner so that it does what you want it to do, however as far as the scanner software is concerned it is still running the original protocol.

I only hope GE don't decide they need to lock down the scanners even further. For "confident" users (see TFA) who want/need to try out different protocols it will only mean more dangerous hacking of the scanner settings. Confident users with NIH research grants should take note.

Re:Default setting... (0)

Anonymous Coward | more than 4 years ago | (#29746875)

The setting in this issue was not lethal, but was 8x more than needed to do the diagnostic.

They had used this setup for 18 months before a patient complained about hair loss. They went back and found hundreds of people had been overdosed.

They must somehow audit the actual radiation released to cover the less-than-lethal-but-more-than-therapeutic cases.

Re:Default setting... (1)

DomNF15 (1529309) | more than 4 years ago | (#29746925)

Agreed - looks like the embedded software developer didn't follow tenet 1 of the soft dev. process, i.e. assume the user is an idiot. It should always default to some "safe" value.

Re:Default setting... (1)

mysidia (191772) | more than 4 years ago | (#29747219)

Then a simple input error while administering it, causes an overdose...

HULK MAD! (5, Funny)

BumbaCLot (472046) | more than 4 years ago | (#29746477)

Even under normal circumstances, the procedure requires more radiation than most other types of CT scans, said David Brenner, director of radiological research at Columbia University Medical Center in New York.

Anyone else read this as David Banner?

Re:HULK MAD! (1)

philpalm (952191) | more than 4 years ago | (#29746715)

Hulk would be mad if his flash drive gets erased by the radiation. Then again since he tears off his clothes because of the radiation, he doesn't need no stinking flash drive...

Re:HULK MAD! (3, Insightful)

frito_x (1138353) | more than 4 years ago | (#29746907)

Hate this "immediately moderate when you select an option" feature. meant to mod funny... slip of the mouse goes to overrated... there should be a go/ok button next to the list imho.

wasted 3 mod points... oh well...
     

Pretty narrow margin (1)

Rising Ape (1620461) | more than 4 years ago | (#29746515)

The error went unnoticed for the next 18 months, until this August, when a stroke patient informed the hospital that he had begun losing his hair after a scan.

There's only a factor of 8 difference between a typical scan dose and one large enough to cause hair loss and skin damage? IIRC observable damage doesn't occur until the hundreds of mSv range. I'm pretty astonished that CT scans need such huge doses.

Re:Pretty narrow margin (1)

argent (18001) | more than 4 years ago | (#29746667)

There's only a factor of 8 difference between a typical scan dose and one large enough to cause hair loss and skin damage?

Yeh, that's what I was thinking. I thought that X ray machines were designed to stay well away from dangerous levels these days. I'll keep that in mind next time my doctor suggests a CT scan.

Re:Pretty narrow margin (1)

O('_')O_Bush (1162487) | more than 4 years ago | (#29746719)

Well think about it for a sec. They're getting high resolution images of tissue and fluid, not just bone.

You would expect that to require large, large doses to achieve.

Re:Pretty narrow margin (2, Informative)

celticryan (887773) | more than 4 years ago | (#29746989)

Re:

100s of mSv range

There are portions of the world that have a very high natural background in the 200 mSv range so you are not quite right with your estimates. In addition, you have to distinguish between whole body dose and localized dose. It is not uncommon to see tumor doses in the 40-50 Sv range.

The machines were set for .5 Gy (for xrays 1 Gy = 1 Sv) and got 3-4 Gy. A whole body dose of just above 4 Sv is a 50% death in 3-6 weeks (with no medical intervention). (remember that the CT was only to the brain). They are definitely in some dangerous territory, but the article said the median age of the patients was 70. Couple that with the fact that they already had a stroke and it is safe to conclude that long term effects are unlikely to matter.

Re:Pretty narrow margin (1)

Rising Ape (1620461) | more than 4 years ago | (#29747149)

The high natural background areas deliver the 200 mSv over a period of a year though, not a matter of minutes.

There may be good medical reasons for using such enormous doses, but it still took me by surprise. The average dose of a nuclear worker is only a few mSv/year. Still, I guess a 1 in 40 chance of the radiation causing a fatal cancer isn't so bad if it stops you dying from a stroke in the meantime.

Re:Pretty narrow margin (1)

Amouth (879122) | more than 4 years ago | (#29747005)

but CT scan's aren't "typical" - you get xray'ed couple times a year so they are very low poweed, but a CT scan?? i think my last was? i might have had one 25 years ago when they cut my head open, for that they pump up the power to get it right.

Re:Pretty narrow margin (1)

hattig (47930) | more than 4 years ago | (#29747081)

If you read the article, you would have seen that this type of scan requires a higher dose of radiation, as it is picking up the iodine in the bloodstream.

On the upside, they would have got some really good images.

Maybe testing it afterwards? (3, Insightful)

uncledrax (112438) | more than 4 years ago | (#29746523)

Maybe next time they will test the damn thing before subjecting patients to it? It's a built in part of my job that I test/confirm a change after I make a change.. because often there's a likely hood of something unexpected or improperly explained that can cause an issue.

How hard would it have been to stick a dosimeter in the machine after the change and run it though a test?
(I realize that just a basic dosimeter might not be a sufficient measure.. but it would have been good to get a before/after.. and something like a 8-fold increase would have been easily detectable!)

Re:Maybe testing it afterwards? (1)

jeffb (2.718) (1189693) | more than 4 years ago | (#29746599)

Maybe next time they will test the damn thing before subjecting patients to it? It's a built in part of my job that I test/confirm a change after I make a change.. because often there's a likely hood of something unexpected or improperly explained that can cause an issue.

So, what you're saying is, "Always mount a scratch human."

Re:Maybe testing it afterwards? (0)

Anonymous Coward | more than 4 years ago | (#29746669)

I call out your copypasta from Fark.

Re:Maybe testing it afterwards? (0)

Anonymous Coward | more than 4 years ago | (#29746897)

Somebody repeated a twenty year old joke on Fark? GTFO!

Re:Maybe testing it afterwards? (0)

Anonymous Coward | more than 4 years ago | (#29747003)

So, what you're saying is, "Always mount a scratch human."

You're my hero.

Re:Maybe testing it afterwards? (0)

Anonymous Coward | more than 4 years ago | (#29746731)

Can't an "X-ray Pancake Geiger Tube" measure x-rays? How about just having one in the field of the machine running all the time. Good old analog hardware to confirm your digital settings.

Kind of like how people who work in nuclear power plants understand that just because you're getting no errors.... it doesn't mean that everything is ok.

Re:Maybe testing it afterwards? (5, Insightful)

RDW (41497) | more than 4 years ago | (#29746887)

'How hard would it have been to stick a dosimeter in the machine after the change and run it though a test'

Supposedly the actual dose would have been displayed on the machine's screen (I wonder how prominently?):

http://www.latimes.com/news/local/la-me-cedars-sinai14-2009oct14,0,5065886.story [latimes.com]

'"It's in your face on the screen," said Dr. Donald Rucker, chief medical officer for Siemens, a manufacturer of CT scanners.'

'CT technicians are trained to monitor dose levels, and some hospitals conduct checks before every scan..."There are other places where the techs might be operating more as button-pushers," said Dr. Geoffrey Rubin, a professor of radiology at Stanford University. "The user becomes a little blind to these numbers."'

Re:Maybe testing it afterwards? (1)

mysidia (191772) | more than 4 years ago | (#29747297)

This is the problem.. not enough human validation of the machine's output.

It's equivalent to Windows users just clicking Yes/Ok/Run every time, without reading the dialog box.

As a Windows user, you'll eventually get infected by malware or let some serious harm come to your system unchecked.

As a CT Technician... someone could die... the hospital procedures that allow this are inexcusable.

Not running through the new process at least once on each machine, with careful observation, or some method of measuring the dose, to ensure correctness, equally inexcusable.

That meant resetting the machine to override the pre-programmed instructions that came with the scanner when it was installed.

Note the device was programmed to do a certain thing, they for themselves decided they knew better, overrode programming and safety protocols, and configured it to do something else. Then they failed to take some type of action to safely test that new config.

Re:Maybe testing it afterwards? (1, Insightful)

Anonymous Coward | more than 4 years ago | (#29746999)

Good job not reading TFA.

In fact, the article notes that the Therac-25 ran successfully for some time before injuring the first patient. One example cited that a machine operator who ran through the dosage screen too quickly caused a race and a resultant incorrect dosage. How many times do you test your complete software system for overall race conditions like that?

On the other hand, you're right in guessing that there should have been (many) hardware interlocks on the machine to prevent dangerous or lethal doses from occurring, and that was the lesson in the article.

Slashdot editors: please provide a "Did not read TFA" button on posts so we can immediately mod those brainiacs that couldn't be bothered to read the original article from being marked "+5, Insightful."

Re:Maybe testing it afterwards? (1)

uncledrax (112438) | more than 4 years ago | (#29747183)

"Good job not reading TFA."

Correct.. I did not read the (included for historical and anecdotal purposes, but otherwise not relevant to this incident), Therac-25 article.. Instead I read the LATimes article that this story is about, and the FDA recommendation.. neither which had "One example cited that a machine operator who ran through the dosage screen too quickly caused a race and a resultant incorrect dosage."

Good job reading the wrong article :]

The personal jab aside, you're correct in that you cannot test every condition, they will "always build a better idiot"; however in this case it, based on the FDA and LATimes articles, it seems that just measuring the dosages would have been sufficient to reveal this problem. Yes, if it is displayed on the monitoring equipment (I'm not a radiologist, so I don't know), then yes, the operator should know what is a safe dosage.

not idiot proof enough (2, Interesting)

HNS-I (1119771) | more than 4 years ago | (#29746531)

While the hospital shouldn't have gone and reprogram the instructions, this should have been prevented at hardware level. The machine should register a patient checking in and the amount of radiation emitted.

In short (2, Insightful)

Cornwallis (1188489) | more than 4 years ago | (#29746539)

Will we ever learn enough to make these errors truly uncommittable?"

No.

Silver lining (1)

Wilson_6500 (896824) | more than 4 years ago | (#29746553)

Doctors are woefully unaware or unwilling to admit that CT scans do involve some risk because they very well can give appreciable radiation dose, often far more than that of standard radiography. They are largely viewed as harmless given the excellent volume of anatomical information they provide, and while they do offer immense benefit, it is vital that the radiation hazard be comprehended. I hope that doctors and technologists will take away from this the lesson that they do need to be aware of radiation safety and radiation risk (and some basic medical physics) even if radiation is not their primary specialty. It's not just the health or medical physicist's problem.

Re:Silver lining (0)

zonker (1158) | more than 4 years ago | (#29746671)

If you want to get a better understanding as to why doctors are so quick to toss you into a CT scanner, listen to the most recent episode of This American Life [thislife.org] . It goes into the minds of doctors and why they use tools that aren't always even medically necessary and also explores the insurance industry and patients too. Very interesting stuff.

Re:Silver lining (1)

ircmaxell (1117387) | more than 4 years ago | (#29746939)

I wonder how much of it is for the insurance $$$, versus how much of it is to cover their arses... Malpractice is such a real threat to MDs these days, that many of them just will throw any test at you if there's even the slightest chance of an issue. Part of it is ignorance, part is laziness, and part is fear... Who's to blame?

"Unwilling to admit"? Hardly. (1)

jeffb (2.718) (1189693) | more than 4 years ago | (#29746681)

I think doctors, machine designers, and everyone else involved are aware of the increased radiation associated with CT scans. But if you've got someone presenting with stroke symptoms, you're balancing "additional 1 in 10,000 lifetime risk of cancer" against "irreversible brain damage increasing in severity with each passing minute". If I'm ever in that situation, I'd tell them "cook me as hard and fast as you like, and I'll deal with the side effects at my leisure."

No, there will always be risk (1, Interesting)

e2d2 (115622) | more than 4 years ago | (#29746577)

When I witness this constant chase of removing risk from the world it makes me wonder if it's delusion or just plain stupidity. No matter how hard you try there will always be risk involved in almost every action. Accept it and treat it rationally. I'm not saying to ignore it. Just to accept it as life. Life is brutal.

Re:No, there will always be risk (2, Insightful)

Entropius (188861) | more than 4 years ago | (#29746701)

Life is brutal, but that doesn't mean we should give up on trying to make it less so. Asking whether CT scanners can be redesigned to make this not happen, and whether it's worthwhile to do so, is very valid.

Re:No, there will always be risk (1)

ColdWetDog (752185) | more than 4 years ago | (#29746841)

It isn't removing the risk that's an issue - it's calculating the risk benefit ratio and, in this case, understanding what you're doing. While we don't have enough information to really know what happened (not that this sort of this ever stops us here), it seems like the staff the overrode the built in protocols didn't think it through well enough or perhaps didn't RTFM.

It is heartening to note that at least the new GE Brightstars's print out the radiation exposure given with each study as part of the routine patient data. That little bit was FDA mandated. (They also run Linux, but that isn't germane to this discussion.)

I am a bit surprised at all this. I would have thought that any changes to the defaults that clearly did not result in a lowering of radiation dose (which TFA notes is fairly common) did not involve a careful step through of what exactly would happen. These machines are pretty damn complicated.

Re:No, there will always be risk (1)

eleuthero (812560) | more than 4 years ago | (#29747237)

How far does "acceptance" go? Being horrified at problems and seeking to address them seems like a proper response--humans are not just machines--emotional responses indicate acceptance on many levels, not just the intellectual.

And while this may or may not apply to your particular comment (depending on your meaning), if we didn't work to remove unnecessary risk from the world, there would be no fire, no stick clubs, and we would all be living in trees trying to hide from tigers and lions--when they didn't just climb up right after us. Many would die before reaching child-bearing age and malnutrition would be constant. I happen to like a world where we try to improve the quality of life.

Medical Staff were a big part of the problem (4, Interesting)

CheddarHead (811916) | more than 4 years ago | (#29746617)

Along with the usability issues with the design of the Therac-25 it's obvious that the attitude of the medical staff contributed greatly to the problem. Patients complained of being burned, but their complaints were essentially ignored. Meanwhile, they were sent back for multiple treatments. Overwhelming evidence of radiation burns was ignored or given only cursory investigation because medical personal or manufacturer reps claimed that it was impossible for the Therac-25 to be responsible for the burns.

uncommittable error? (0)

Anonymous Coward | more than 4 years ago | (#29746619)

"Will we ever learn enough to make these errors truly uncommittable?"

NO!

Make something idiot proof, and they invent a better idiot!

8 times intended != fatal (1, Insightful)

140Mandak262Jamuna (970587) | more than 4 years ago | (#29746629)

Before you all get worked up realize that 8 times the intended dose does not mean it was over the exposure limit or dangerous levels. That too just 200 people. Come on get some perspectives ok? It was not long ago we were permitting shoe salesmen to Xray the foot to check the fit of shoes on people. And it was not even pulsed. Continuous, high level radiation.

For comparison remember more people are killed by vending machines and by falling off the roof putting up the christmas lights.

Re:8 times intended != fatal (1)

northernboy (661897) | more than 4 years ago | (#29747299)

Actually, the levels >were over dangerous levels. Admittedly, not fatal. Fun fact: they first identified the problem when a patient (victim?) reported losing his hair after the scan. The follow up LA Times article today says that when the hospital contacted the 206 patients, 80% reported losing hair after their scans. That's pretty serious exposure.

Oh, another fun detail: the dose administered IS DISPLAYED ON THE FRONT PANEL AFTER THE SCAN!!! In 18 months, nobody ever questioned why the level was so high. If the machine delivers the dose according to the program, it must be right, evidently...

Meh... (2, Funny)

Machupo (59568) | more than 4 years ago | (#29746631)

What's a few hundred rem among friends?

The errorless machine... (4, Insightful)

TemporalBeing (803363) | more than 4 years ago | (#29746643)

Will we ever learn enough to make these errors truly uncommittable?"

There is and never will be such a thing as a machine without the possibility for error. And you'll never get around the old adage/rule - If it can happen, it will. How often it occurs it the key; and while we should always aim to make an error-less machine, it is an impossibility and we can only achieve it by make the occurrence of such errors as few and far between as possible.

After all, an error-prone human must be involved to make the machine; even if that machine made another machine a human was still involved at some point to make the original. Thus there will always be the possibility for errors. Even if, as demonstrated by the Matrix, iRobot, and many others, the machines make that error on purpose to save humanity - it is still an error.

Film badges? (2, Interesting)

johnny cashed (590023) | more than 4 years ago | (#29746673)

Would a film badge provide a "check" to determine if the dosage is correct? One x-ray overdose is bad enough, over 200 is really uncool.

Therac-25 (0, Redundant)

Khashishi (775369) | more than 4 years ago | (#29746709)

I thought we'd learned our lesson from the Therac-25. I guess not. Mistakes will always happen, I guess. We need safeguards against radiation overdose, so the program CAN'T provide an overdose above a limit.
http://en.wikipedia.org/wiki/Therac-25 [wikipedia.org]

Re:Therac-25 (0)

Anonymous Coward | more than 4 years ago | (#29746953)

I was about to post the same thing..

This link [ccnr.org] has a little more information. Deadly race condition...

Re:Therac-25 (0)

Anonymous Coward | more than 4 years ago | (#29746955)

If I remember the Therac... the issue wasn't that the machine gave an overdose, it was that the radiation was emitted without the process being completed... so the techs kept trying to complete the process by exposing the patients to multiple doses.

The machine started the process, emitted radiation, then gave a cryptic error. So the techs reset the machine and tried again.

No overdose limit is going to prevent that.

Re:Therac-25 (1)

guruevi (827432) | more than 4 years ago | (#29747287)

The problem is that even those safeguards are ignored or not always wanted. The vendors actually have a lot to do with it too. They want to sell as much systems as possible for the lowest cost. A lot of the safeguards are thus implemented in software and the same software is shipped to both research sites (where you might want to overdose eg. a mouse) as medical sites (where you don't want to overdose). The only warning you get for most (even dangerous) levels is a pop-up box asking 'are you sure'.

Another problem is that depending on the person, the levels might need to be different. Eg. if you scan a small child you don't want to give it the same levels as an obese adult because it would be dangerous. Therefore safeguards are implemented in software, the front desk puts in the information and the software calculates the levels for you and sends it to the scanner. However if there is an error in weight or size of the person this could easily be overlooked by the tech who needs to churn through 10 other patients in the next hour.

There will always be risks and greed, time and money are a big contributor in these risks. If you want to have better healthcare however, you'll need to invest in it. These scanners are not cheap and are usually overbooked. The biggest problem in the US is that these scanners need to be funded privately by the institution and then later the costs are recovered through private insurance companies that usually give a big fuss about the price of these things, the prices get negotiated to anywhere between 10% and 30% of the actual price and thus you have an underfunded, overbooked imaging department.

Don't be such a wuss (-1, Troll)

oldhack (1037484) | more than 4 years ago | (#29746711)

Little X-ray never killed anybody.

Re:Don't be such a wuss (3, Informative)

MRe_nl (306212) | more than 4 years ago | (#29747119)

In 1895, Thomas Edison investigated materials' ability to fluoresce when exposed to X-rays, and found that calcium tungstate was the most effective substance. Around March 1896, the fluoroscope he developed became the standard for medical X-ray examinations. Nevertheless, Edison dropped X-ray research around 1903 after the death of Clarence Madison Dally, one of his glassblowers. Dally had a habit of testing X-ray tubes on his hands, and acquired a cancer in them so tenacious that both arms were amputated in a futile attempt to save his life.

Paul Graham On CT Scan Err. (0)

Anonymous Coward | more than 4 years ago | (#29746757)

"Simplicity takes effort-- genius, even. The average programmer seems to produce UI designs that are almost willfully bad. I was trying to use the stove at my mother's house a couple weeks ago. It was a new one, and instead of physical knobs it had buttons and an LED display. I tried pressing some buttons I thought would cause it to get hot, and you know what it said? "Err." Not even "Error." "Err." You can't just say "Err" to the user of a stove. You should design the UI so that errors are impossible. And the boneheads who designed this stove even had an example of such a UI to work from: the old one."

Yours In Elekrogorsk,
Kilgore Trout

Re:Paul Graham On CT Scan Err. (1)

rickb928 (945187) | more than 4 years ago | (#29747387)

Don't blame the UI designers. Blame whoever designed the display to leave out two digits.

It makes sense, in a way. After all, you rarely turn your oven much over 600 degrees, so a 4-digit display makes little sense. 5 digits? You cook what over 9,999 degrees?

From then on, all other decisions are compromised.

Sometimes, the interface is hamstrung by the device. The Therac-25 might also be such a case. Safety shutters and all...

IRBs for devices (1)

Improv (2467) | more than 4 years ago | (#29746783)

Perhaps having the equivalent of IRB review over any changes to devices of this sort would help prevent such problems. It makes sense for devices to be reconfigurable, and it makes sense for devices to try to warn people away from doing stupid things. In this case, they overrode the safeguards, and their judgement happened to be worse than that embodied in said safeguard. That is not always the case - the problem is when people make changes with potantially lethal consequence and there are not enough eyes on those changes.

IRBs were designed to help mitigate such problems with ethics - researchers lack the breadth of perspective and have a potential conflict of interest were they to judge appropriate research ethics on their own. The IRB acts as a second check on proposed experiments. Similar things with devices of this sort (X-rays, MRI scanners, etc) might prevent similar issues.

Feedback? (4, Interesting)

TopSpin (753) | more than 4 years ago | (#29746789)

Will we ever learn enough to make these errors truly uncommittable?"

No. As long as correctness can't be proven and operators are permitted to create unanalyzed conditions by altering protocols there will always be risk. There are probably other mis-configured CT scanners out there in use right now that have been overdosing patients for years.

CT scans use X-rays; an easily detected frequency of light. Why not require that scanners incorporate an independent detector that measures the amount X-ray energy? If that is possible then create an interlock that can shut down the emitter when the net energy gets out of bounds and require that any such incident be NRC reportable. If the detector excluded from alteration by the operators then software bugs, misunderstandings, etc. can be detected even years after the last engineer had contact with the system, either before harm is done or at least before hundreds of patients are literally burned.

Re:Feedback? (1)

_LORAX_ (4790) | more than 4 years ago | (#29747273)

A hardware X-Ray "circuit breaker" that would physically trip the power to the CT scanner if levels are exceeded? Not a bad idea. I would also require a monthly/quarterly test of the equipment by intentionally running it slightly over it's rated threshold.

What is amazing (1)

al0ha (1262684) | more than 4 years ago | (#29746793)

Is the lack of patient participation in their own health initiatives.

Approximately 90 people over 18 months suffered hair loss and/or burns on their head, and not one of them reported it.

Patients need to wake up and realize doctors and the medical establishment try to do their best, but they are only human and a vast majority of what they do is simply educated guessing.

The patient is ultimately responsible for his/her own health care, so drill the doctors and do not let them get away with brushing off your concerns. You know your body best, not the doctor - even though their degree generally makes them think otherwise.

Put a dosimeter in there with the patient (2, Insightful)

ggraham412 (1492023) | more than 4 years ago | (#29746853)

For patients undergoing scans or treatments involving radiation, why not verify exposure with a 25 cent dosimeter? You'd catch problems right away.

Failsafe anyone? (1)

Seth Kriticos (1227934) | more than 4 years ago | (#29746891)

There are very strict regulations on what radiation is acceptable. Why did the not add a failsafe or critical warning, something like a big red blinking message "What you are gonna do is probably stupid" or so?! Just to give the therapist a hint that something is wrong. I mean, implementing this kind of failsafe should not pose that much of a problem, would it?

Set Phasers on Stun (1)

Jeff Satterley (1622949) | more than 4 years ago | (#29746923)

Reminds me of my Human Factors class, we read the book Set Phasers on Stun [amazon.com] , which included horror stories about human design disasters.

Hulk? (1)

HaaPoo (696098) | more than 4 years ago | (#29746927)

So are these guys are going to turn gray and nobody should piss them off?

Re:Hulk? (1)

MickyTheIdiot (1032226) | more than 4 years ago | (#29747137)

Actually, Hulk turns green right now. So says Peter David.

Dev is behind schedule! Forget testing.... (1)

gestalt_n_pepper (991155) | more than 4 years ago | (#29746963)

Sound familiar to anybody? Hope you enjoy that next doctor visit, plane ride, etc.

Hey, I hear they want to make a smart grid! Any takers on reliability? Anybody?

Oh great (2, Funny)

Tony Hoyle (11698) | more than 4 years ago | (#29747091)

Now there are 206 hulks running around.

Just don't make them angry.

a rational question (1)

rs232 (849320) | more than 4 years ago | (#29747241)

Does anyone here who posted on the subject, know what the fuck they are on about. And can we really believe the published reports ..

Programmer Oopsie! (1, Interesting)

Anonymous Coward | more than 4 years ago | (#29747249)

It's just a programming bug, it will be fixed in the next release.

Software is licensed and may include 'defects' and customers have no choice but to accept defects.

Maybe if these "software engineers" could be held liable for any defects, things would change.

But hey, they are just programmers, put the bug into twiki/bugtracker, and try and fix it in the next release.

Make sure all your easter eggs are working though.

And you think more IT will make things better? (1, Insightful)

Anonymous Coward | more than 4 years ago | (#29747281)

So, if this CT error bothers you, do you really think the onslaught of IT technology being thrust at hospitals is going to make things in health care any better? The Obama Administration is creating a feeding frenzy among the IT companies to rush in and collect their piece of the pie. To do this, they are creating electronic health records and connecting medical devices to regular IT networks. Who is testing that stuff? Mind you, I don't think Obama's move is necessarily bad, just the blind faith driving it that more technology is always a good thing. Even NASA finally figured out that their "Faster, Cheaper, Better" programs didn't mean "Faster + Cheaper = Better."

Granted, the Silicon Valley/Redmond group have created some remarkable technology, but should we take for granted they are doing all the right things in areas they've never worked in before? It seems to me we all put way too much faith in our technology... as illustrated by the comments that this CT should correct for all potential errors a human might make. If this were really the case, why is there still so much crappy hardware and software out there?

superior private healthcare (0)

Anonymous Coward | more than 4 years ago | (#29747325)

Only with the superior private health care system of the United States can you get 8x the dose of radiation in your CT scan!

I'll... I'll show myself out.

soft error (1)

viralMeme (1461143) | more than 4 years ago | (#29747353)

"There was a misunderstanding about an embedded default setting applied by the machine . . . ," officials at the renowned Los Angeles hospital said in a written statement that provided no other details about how the error occurred. "As a result, the use of this protocol resulted in a higher than expected amount of radiation."

The dose of radiation was eight times what it should have been.

Once the scanner was programmed with the new instructions, the higher dose was essentially locked in. Each patient who got the procedure -- known as a CT brain perfusion scan -- was subjected to the overdose ..

Does that mean there was a programming error. Who wrote the new protocol, who implimented it, who was responsible for testing it? And why isn't there a sensor in the device that sounds an alarm if the radiation exceeds a safe limit?

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