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Brain CT radiation Snafu prompts FDA alert.

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Brain CT Radiation Snafu Prompts FDA Alert
The U.S. Food and Drug Administration (FDA) has
asked all medical facilities and radiology personnel involved in brain perfusion computed tomography (CT)
to double-check their equipment to ensure that patients are not being exposed to excessive doses of radiation.
The October 8 FDA alert followed reports that 206
patients undergoing scans for stroke diagnosis at
Cedars-Sinai Medical Center, in Los Angeles, were exposed to as much as eight times the acceptable radiation dose for such testing when the wrong protocols
were entered on a General Electric (GE) Healthcare
multi-slice CT unit.
The error went undetected for 18 months, and only
came to the hospital’s attention in August, after several
patients reported losing patches of hair and erythema.
Once the mistake was discovered, the center notified
the California Department of Health and shut the machine down during the investigation.
“There was a misunderstanding about an embedded
default setting applied by the machine,” the hospital
explained in a statement.
The unit has since been recalibrated and is back in
use, according to the hospital. In its summary, the
FDA said that instead of receiving 0.5 Gy (maximum),
patients received 3 to 4 Gy. About 40 percent of the
patients experienced some temporary patches of hair
loss and/or skin reddening.
The FDA’s alert summarized the exposures without
specifically naming Cedars-Sinai.
“While this event involved a single kind of diagnostic test at one facility, the magnitude of the overdoses
and their impact on the patients were significant,” according to the FDA. “This situation may reflect more
widespread problems with CT quality assurance programs and may not be isolated to this particular facility
or this imaging procedure.”
A spokeswoman for the FDA said the federal health
agency is investigating whether the overdoses were
caused by the device or the procedures that were followed.
In a statement, GE Healthcare said that it is cooperating with FDA officials investigating the accident,
although company representatives said that there were
no “malfunctions or defects” in any of the equipment
Annals of Neurology
November 2009
It is not known whether other hospitals or healthcare facilities using the same GE scanners have experienced similar problems.
The same day the FDA released its alert, CedarsSinai was named one of the state’s top performing physicians’ organizations, for the fifth straight year, by the
Integrated Healthcare Association (IHA), an industry
trade group that promotes “quality improvement, accountability and affordability of health in California.”
‘An Important Reminder’
Max Wintermark, neuroradiology division chief at the
University of Virginia, in Charlottesville, said the incident underscores the importance of reviewing emission
levels for each procedure, regardless of protocol presets.
“With perfusion CT scanners, you save the protocols
for different types of scans when the unit is delivered,
usually with the manufacturer’s help. For the remainder of the scanner’s life, you simply call up the protocol for the procedure,” he explained.
The system is practical because it standardizes test
parameters so that the exact same ones are used for
each test.
“The problem with this is that technicians and radiologists often assume the settings are always on-target
and tend to forget to double-check them for each session,” Wintermark told NerveCenter.
“This incident has sent an important message to all
of us – reminding us that we need to look at these
levels more often. We cannot simply set them up and
forget about them. Technicians need to check the parameters and radiation dose every time, and the radiologist should regularly check them too.”
In order to prevent similar accidental overexposures,
the FDA asked every facility performing CT imaging
to review its protocols and be aware of the dose indices
normally displayed on the control panel. These include
the volume computed tomography dose index (abbreviated CTDIvol, in units of “milligray” or “mGy”) and
the dose-length product (DLP, in units of “milligraycentimeter” or “mGy-cm”).
Hospitals, clinics and CT testing facilities, radiologists, neurologists, neurosurgeons and associated radiology department managers should ensure that the values
displayed always correspond to the acceptable doses for
each protocol, and to confirm them again after each
session, the agency said.
Hospital Responds
Officials at Cedars-Sinai admitted that the CT problem went undetected for a year and a half.
On October 14, Barry Pressman, chairman of the
medical center’s imaging department, issued a second
statement that seemed to downplay the incident. He
noted that the amounts of radiation the patients received were no greater than those used in certain invasive procedures.
“These patients received an amount of radiation in a
CT brain perfusion scan that was higher than expected,
but similar to an amount they might receive when undergoing a procedure such as angioplasty.”
Once the problem was discovered, he said, the hospital contacted all patients who underwent CT scans
during the period in question and addressed any concerns and questions. Nonetheless, some patients have
told reporters that they were not contacted or adequately informed of the risks.
“I sincerely regret if any patient feels that they did
not receive the information they needed,” Pressman
The following day, Thomas M. Priselac, the center’s
president and CEO, issued a more comprehensive
statement, along with a list of measures that CT manufacturers might adopt to avert future occurrences.
“To have this situation occur in any patient is unacceptable,” he said, before outlining the results of the
Center’s internal investigation and describing changes
Cedars-Sinai would make in its internal protocols to
prevent such accidents in the future.
These included changes to assure proper validation
of radiation levels at the time protocols are changed,
improved access control over protocol changes and additional redundancy in the methods used to confirm
radiation dose levels.
“As part of our investigation . . . we have also identified information that we believe may be helpful to
the FDA, scanner manufacturers and other hospitals,”
he said. “We present this information not to shift responsibility, but to maximize patient safety.”
The Cedars-Sinai recommendations to the FDA and
equipment manufacturers help explain how the accidental exposures occurred.
According to the hospital, the protocol for the CT
brain perfusion study was changed in February, 2008
and “based on our understanding of the machine’s
auto functions, it should not have delivered an excessive dose.”
However, the embedded default setting for image
noise in the auto function in the 64-slice scanner,
which was supplied by the manufacturer, did not
match the manufacturer’s recommended settings.”
As a result of the default’s lower noise setting, the
amount of radiation delivered was higher than expected, the hospital asserted.
The hospital also cited the need for improved scanner displays, noting that they could be enhanced to
make their use easier, especially for time-sensitive scans
such as CT brain perfusion, and that an industry standard method of displaying radiation dose units should
be developed, “one that is consistent with the nomenclature used in training programs.”
Units also need an automated reminder function, according to the hospital. Currently, there is no forced
function on the equipment requiring technologists to
proceed with the scan only after confirming they have
reviewed the appropriate dose, the hospital said. Moreover, “more assertive” audible or visual alerts on the
scanners could warn operators of excessive doses.
Finally, the hospital encouraged industry to adopt
greater use of passwords, especially where incorrect settings pose a greater risk to patients.
A GE Healthcare spokesman said that while the
company is unable to comment on any specifics on the
incident because of potential litigation, it did not believe there was any problem with the equipment used.
Malpractice Fallout
A class action lawsuit was filed on October 20 by
Trevor Rees, who underwent two scans at the center,
and 100 “John Doe” plaintiffs. The action names both
Cedars-Sinai and GE Healthcare Technologies, the
manufacturer of the scanner used, as well as GE itself.
According to the lawsuit, Rees “was not only subjected to an overdose of radiation, but faces a higher
risk of cancer, expense of longer-term health monitoring of its effects, and suffers severe and serious physical
and emotional damage.”
It also charges that hospital officials who contacted
Rees nine months after the scans asked him about experiencing any side effects, but did not mention that
there was a problem with the CT’s settings.
“There was no mention of radiation to me on the
phone at all,” Rees said in a statement issued by his
Los Angeles attorney, William Newkirk. “I never
thought anything more about it until I saw the news
about five days later.”
Rees filed the 19-page complaint in Los Angeles Superior Court, seeking to represent “all individuals who
received CT brain perfusion scans at [Cedars-Sinai]
from February, 2008 until August, 2009, or at any
other medical or imaging facilities utilizing CT imaging machines manufactured by [GE Healthcare], during the two-year period preceding this action.”
In a statement, attorney Newkirk said that he believes the problem is widespread.
“This isn’t just a Cedars-Sinai problem. We believe
that because of the way the machine is manufactured
Annals of Neurology
November 2009
and explained to medical users, there is a very good
chance that this same situation has been or is being
played out in radiology departments across the country.”
Cases of prolonged exposure to CT radiation during
head or brain scans occur occasionally, but are believed
to be relatively rare. Most tests involve exposure for
two to three minutes.
One year ago, however, a two year old boy in the
community of Mad River, near Sacramento, California, was scanned for almost an hour after complaining
of neck pain after a fall – more than 150 individual
exposures. The administering technician was reprimanded by the hospital, but she contested her state
license revocation and did not actually lose her license
until eight months after the incident.
In contrast to the young boy, the median age of the
overdose victims at Cedars-Sinai was 70.
Wintermark also believes improving safeguards and
quality control over CT protocols can avert similar
problems. Further, he said many CT manufacturers already offer tools that can help.
“As it was, there was no validation process at
Cedars-Sinai that would have identified the problem
any sooner,” he told NerveCenter. “This could have
happened anywhere. But remember, there are thousands of CTs done every day in this country, and I
think it is safe to say the overall safety record is excellent. Sometimes airplanes crash, but it is still the safest
way to travel.”
Kurt Samson
in the Annals...
One hundred twenty-four consecutive cases of Creutzfeldt-Jakob disease (CID) in France, verified by biopsy or
autopsy between 1968 and 1977, were analyzed with respect to their clinical characteristics. The series comprised equal
numbers of men and women, with the most frequent age at onset being 60 to 64 years and the most frequent duration, two to three months. A prodromal illness was observed in more than one-third of the patients. Clinical presentations and symptom frequencies are tabulated, and a multifactor analysis has been performed to obtain those combinations of symptoms and signs which occurred at least as often as the triad of dementia, myoclonus, and a positive
electroencephalogram. Two groups of atypical cases are also emphasized: one with sudden, strokelike presentation and
rapidly evolving illness of less than 2 months’ duration, and the other with a long clinical course of between 2 and 10
Annals of Neurology
November 2009
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snafu, radiation, alert, prompts, brain, fda
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