An estimated 206 patients at an unnamed healthcare facility have received CT scan radiation doses that were eight times normal levels, the federal Food and Drug Administration warned.
The agency said yesterday the overdose exposures came about during multi-slice CT imaging to diagnose and treat stroke over an 18-month period. The agency, which said it is investigating the incidents, did not release the hospital's name, location or period of time the excessive radiation doses occurred, saying only that it "has become aware" of the overexposures.
"Instead of receiving the expected dose of .5 Gy (maximum) to the head, these patients received 3-4 Gy (a unit of absorbed radiation dose due to ionizing radiation). In some cases, this excessive dose resulted in hair loss and erythema (redness of skin). The facility has notified all patients who received the overexposure and provided resources for additional information," the agency said.
The FDA called the magnitude of the overdose "significant" and said it may reflect more widespread problems with CT quality assurance programs, "and may not be isolated to this particular facility or this imaging procedure (CT brain perfusion)."
Lower doses of radiation than 3-4 Gy, but which are higher than .5, may not cause obvious radiation injury, but underlying problems "may go undetected and unreported, putting patients at increased risk for long-term radiation effects," the FDA said.
FDA officials added they are "working with the parties involved to gather more data about this situation and to understand its potential public health impact. As FDA obtains more information that better defines the problem, we will be better able to determine if there are more widespread risks."
The notification was distributed to CT facilities, emergency physicians, radiologists, neurologists, neurosurgeons, radiologic technologists, medical physicists, and radiation safety officers.
The agency urged hospitals and other users of CT devices "to report deaths and serious injuries associated with the use of medical devices," including adverse events related to CT devices that do not meet requirements for mandatory reporting."
Earlier this year, California health officials fined Mad River Community Hospital in Arcata, CA, $25,000 because of an incident in January 2008 that put one youngster in immediate jeopardy.
A 23-month-old boy was given a massive radiation overdose during a series of 151 CT scans of his cervical spine over a 65-minute period.
The patient, Jacoby Roth, received an estimated 2.8-11 Gy, much higher than the dose he should have received. The child had been admitted to the emergency department for a possible neck injury resulting from a fall out of bed at home. An X-ray showed a possible injury.
The child's injuries included redness on the patient's left and right checks. The boy's parents have filed a lawsuit alleging medical malpractice and battery. An expert epidemiologist has suggested the child is at increased risk of cancer.