http://www.cnn.com/2007/HEALTH/11/28/dangerous.scans.ap/index.html
Millions of Americans, especially children, are needlessly getting dangerous radiation from "super X-rays" that raise the risk of cancer and are increasingly used to diagnose medical problems, a new report warns.
Will this dent the proliferation of clinics in mall doing whole body scans for healthy people?
Graham Chiu advised me against having one last year, I think commenting that there was a high risk from having a CT Scan. At least in the UK we don't have any Shopping Malls offering that service -- maybe we're next.
Graham? Can you give any more detail?
Nick
Nick Harrington email me or Skype: nickharrington emrupdate.comIf I have seen further it is by standing on the shoulders of Giants" Sir Isaac Newton 1676
"Dr. Robert Smith, the American Cancer Society's director of screening, said the authors' estimate that 2 percent of future cancers may be due to CT scans "seems high." But since cancers take 10 to 20 years to develop, "the ability to even observe that kind of an increase is going to be very difficult," he said."
I agree with Dr. Smith wholeheartedly.
As much as I agree with the contention that we are sometimes being exposed to too many scans, this report is NOT a real scientific study, and it's thesis of a whooping 2% extra cancer risk will be difficult to prove. It will require that one day we compare prospectively 2 groups of patients from the same community-
The end points should not only include the incidence of cancer, but OVERALL SURVIVAL, since who cares if you get even the inflated 2% extra malignancies if the scans help detect disease processes at a curable state leading to increased overall survival.
This was done with chest radiographs over the past 30 years- there are numerous studies that have shown that CXRs don't increase survival in patients who smoke. They just detect the cancer sooner, but they die at approximately the same age as a group than those who only get the CXR after symptoms ensue. This is so established as to be one of the perpetual medical Board question included almost yearly in the USA tests.
My hospital last year began doing "executive physicals" that almost caused a riot among the admitting docs. They were primarily going after patients that go for the questionable "preventive" CT scan series to bolster their financial pockets, but at the same time they were stealing the richest, least ill patients from the medical community from the very admitting docs that they so depend on. So you don't have to go to shopping centers to find unscrupulous people in the medical community.
We are using CT scanning more than ever before for USEFUL purposes, s.a. CT coronary and renal angiography. Recently there was even an editorial in the NEJM calling for the use of CT "virtual" colonoscopy to replace a full colonoscopy. The sensitivity of a full colonoscopy is 88% and of a virtual colonoscopy 86%. For every 100 patients that undergo a virtual colonoscopy, in only 8% a polyp or other irregularity will be found that will require a full colonoscopy. The cost of a virtual colonoscopy is about $800 in my area and about $1800 for a full colonoscopy. The 1/600 risk of perforation can be avoided in the majority of virtual colonoscopy patients. So a switch would be not only safer, but less costly to insurers.
You will never get ER docs to stop ordering CT scans in the USA due to the fact that they are under too much malpractice pressure. To decrease these CT scans there would have to be massive tort reform in the USA.
Al Borges, M.D.
● Oncologist in a Small Group Practice in Virginia
● My website URL: http://msofficeemrproject.com/
An Xray here and there is not much of a problem. A rough estimate of the lifetime risk of lung CA from an xray is equivalent to having 1 cigarette.
The problem is.. that a CT chest and abdomen = 250 xrays !
oie.
Today one of my obscessive compulsive disorder (OCD) patients came in angry, complaining that his ventral hernia repair hadn't gone the way he wanted it to, and accusing me of conspiring with the surgeon of somehow hiding the surgeon's mistake, and how we were together in a mafia-like club against him. Then he went on about the NEJM article about xrays and how he's received so many in his life.
I then reminded him that he was 85 years old and in perfect health, except for a possibly slightly ugly ventral hernia repair. He blew his top! Salivating, angry at the world...
I then gave him a referral for a CT scan of the abdomen to look at how the mesh graft had taken... the surgeon would need it to assess the position of the mesh. An ultrasound wouldn't do and an MRI would be too expensive and not covered by his insurance. He blew up...
Thankyouverymuch NEJM! (NOT)
Anyhow, that's how my day began... <sigh> [:'(]
He has a paid subscription to the NEJM?
Graham http://www.synapsedirect.com/ Synapse - the EMR for smart users
It was put out by the Associated Press, so it's everywhere, Graham- Wall Street Journal, Washington Post, etc. Oh well, it's response will pass with time.
Has he ever won lotto?
Does he understand about probabilities?
gchiu: Has he ever won lotto? Does he understand about probabilities?
The fact that lotto exists would indicate that most do not understand probabilities
Back on topic, writing as a cardiologist, CT for CAD screening is absolutely worthless so that any increase in cancer risk outweighs benefit.
>>> CT for CAD screening is absolutely worthless
Andrew, have there been any study to compare the sensitivity of cath angiography vs. spiral CT angiography that corroborates this? Take a look at this report that was just posted on the 'net:
CT Angiography Highly Accurate, Multicenter Trials Show
ScienceDaily (Nov. 27, 2007) - Computed tomography (CT) angiography is as accurate as an invasive angiogram in detecting coronary artery disease, according to the findings of the first two prospective multicenter 64-slice scanner trials presented November 26 at the annual meeting of the Radiological Society of North America (RSNA).
"These two trials with comparable results clearly set the stage for the widespread adoption of and reimbursement for coronary artery CT examinations," said Gerald D. Dodd III, M.D., chair of the Department of Radiology at the University of Texas Health Science Center in San Antonio.
For the Coronary Artery Evaluation Using 64-Row Multidetector Computed Tomography Angiography (CORE-64) Trial, researchers at nine international centers studied 291 patients who were scheduled to undergo invasive coronary angiography for suspected or unknown coronary artery disease. The study found that 64-slice multidetector CT angiography was highly accurate in detecting blockages of greater than 50 percent, with a sensitivity of 85 percent and a specificity of 90 percent. The noninvasive exam was equal in accuracy to invasive angiography in its ability to identify patients to be referred for angioplasty or bypass surgery.
"Reliable assessment of the presence of coronary blockages and accurate prediction of coronary revascularizations are feasible with 64-slice CT coronary angiography," said presenter Marc Dewey, M.D., radiologist at Humboldt University Berlin, Charité, Germany. "Patients with low to intermediate risk of having coronary blockages are most likely to benefit from coronary CT angiography, since in those patients the necessity of invasive angiography is greatly reduced."
The Assessment by Coronary Computed Tomographic Angiography of Individuals UndeRgoing InvAsive Coronary AngiographY (ACCURACY) Trial compared 64-row coronary computed tomographic angiography (CCTA) to quantitative coronary angiography (QCA). The results demonstrated that CCTA is highly accurate in detecting coronary blockages in chest pain patients referred for invasive coronary angiography and is also an effective noninvasive method to exclude obstructive coronary blockages.
Sixteen institutions performed CCTA on 232 patients with typical or atypical chest pain prior to invasive coronary angiography. Findings were then compared to those of QCA, the reference standard used to quantify the results of the invasive coronary angiography.
A total of 82 blockages greater than 50 percent in 49 patients and 31 blockages greater than 70 percent were detected in 28 patients by QCA. Per-patient sensitivity and specificity of CCTA were 93 percent and 82 percent, respectively, for blockages greater than 50 percent, and 91 percent and 84 percent for blockages greater than 70 percent. In addition, negative predictive value was 97 to 99 percent.
"In a population of chest pain patients with a low to intermediate prevalence of obstructive coronary artery blockages, CCTA performed highly accurately compared to invasive coronary angiography," said presenter James K. Min, M.D., assistant professor of radiology and medicine at New York Presbyterian Hospital and director of the Cardiac Computed Tomography Laboratory and Cornell University Medical Center. "These findings demonstrate the high diagnostic performance of CCTA."
Adapted from materials provided by Radiological Society of North America.
URL: http://www.sciencedaily.com/releases/2007/11/071126170854.htm
alborg: >>> CT for CAD screening is absolutely worthless Andrew, have there been any study to compare the sensitivity of cath angiography vs. spiral CT angiography that corroborates this?
Andrew, have there been any study to compare the sensitivity of cath angiography vs. spiral CT angiography that corroborates this?
Writing as an invasive cardiologist, who trained under Spencer King III at Emory, the sensitivity of cath angiography is 100% for detecting coronary atherosclerosis when the angiographer recognizes "luminal irregularities" as coronary disease.
Cath angiography remains the gold standard afterall so that anything else will fall short by default. Moreover, the only adults that do not have coronary disease in the U.S. are folks without visceral adipose tissue (VAT) so that only screening with the gold standard would have any utility because one would be sifting out the uncommon American adults, who do not have coronary disease. The latter would by the math require a test with 100% specificity. Only cath angiography has 100% specificity, again, because it is the gold standard.
>>> Cath angiography remains the gold standard afterall so that anything else will fall short by default.
That may be true, but judging the direction that "virtual colonoscopy" is taking, according to a recent NEJM, endoscopic colonoscopies have an 88% sensitivity while the CT-scan virtual colonoscopy has a sensitivity of 86%, which are statistically equal. The virtual colonoscopy costs $800 while the regular colonoscopy costs $1800.
For every 100 who have a virtual colonoscopy, 8% will end up undergoing a regular colonoscopy, which translates to a savings of $92000.00 for that small group. If the same ends up occurring with the CT angiogram, most likely the savings are going to be greater. If the difference between it and the angiography by cath is minimal, then you'll see the insurance companies calling for the former to be done first, which of course has less chance of perforation and other complications.
I think radiologist future looks very sunny indeed...
alborg: >>> Cath angiography remains the gold standard afterall so that anything else will fall short by default. That may be true, but judging the direction that "virtual colonoscopy" is taking, according to a recent NEJM, endoscopic colonoscopies have an 88% sensitivity while the CT-scan virtual colonoscopy has a sensitivity of 86%, which are statistically equal. The virtual colonoscopy costs $800 while the regular colonoscopy costs $1800.
Different animal. The more appropriate analogy would be invasive colonoscopy for diagnosing familial colonic polyposis. The invasive colonoscopy would definitely be the gold standard with 100% sensitivity and 100% specificity for the latter diagnosis and "virtual colonoscopy" would simply not be able to compete.
In the U.S., coronary atherosclerosis is to the heart as familial colonic polyposis is to the colon.
May this analogy help you understand why CT angiography is worthless except for rare instances where invasive cath angiography fails to clearly define coronary anatomy especially when there are congenital anomalies.
Ok, I'm just a neutral medical guy, not a radiologist or invasive cardiologist, so I don't have anything to gain or lose in this situation. It's important to me in future choices of where to send my patients for their studies.
Today, for example, I've had to send a woman to get an ultrasound to make sure that her post-cath right femoral pain is not associated with a bleed or an aneurysm. She could have averted her pain had she gone for a CT coronary angiogram.
The above study seemed to me to be fairly well designed:
This presentation to the Radiological Society of North America is a pretty big position paper, and it's only 1 week old.
Can you find anything that might have skewed the results enough to negate these findings (i.e. ignore this study)? One thing I see right away is that they probably do have a bias towards radiologic procedures, just as you towards "the gold standard" invasive angiography by catherization.
This is a turf war that the cardiologists will lose ... damm, all that training for nothing!