The U.S. Food and Drug Administration has widened its investigation into radiation overdoses that patients have received from a type of brain scan, suggesting that the problem may be a nationwide issue.
The agency announced Monday that it was looking into possible overdoses at Providence St. Joseph Medical Center in Burbank and a hospital in Alabama.
Providence St. Joseph is now the third hospital in Los Angeles County under investigation for problems with CT brain perfusion scans, a procedure used most often to diagnose strokes.
Unlike the other cases, which involved scanners made by General Electric, the scanner at Providence St. Joseph was made by Toshiba -- adding a new dimension to the investigation.
"Given the fact that we are dealing with two manufacturers and multiple institutions, we wouldn't be surprised" to find problems elsewhere, said Dr. Jeffrey Shuren, acting director of the FDA's Center for Devices and Radiological Health.
Angelo Bellomo, head of environmental health for the L.A. County Department of Public Health, said 34 patients appear to have received excessive radiation at Providence St. Joseph over a 20-month period ending in October.
The problem was discovered by Los Angeles County radiation safety inspectors and reported to the FDA last week, FDA and county officials said.
Patricia Aidem, a spokeswoman for the hospital, said she was unaware of any problems with the scans and that the hospital had always complied with dosing standards.
After overdoses were discovered at Cedars-Sinai Medical Center in August, officials launched inspections of all 11 facilities in L.A. County that offer the scans. That review is now complete, so no more Los Angeles hospitals are likely to be added to the list of those affected, Bellomo said.
In Alabama, Becky Coudert, a 59-year-old teacher, received a CT brain perfusion scan Sept. 8 at Huntsville Hospital, according to her Valencia-based lawyer, Rick Patterson, who is representing several victims from Cedars-Sinai.
The scan ruled out that Coudert had suffered a stroke. But within weeks, there was a bald strip circling her head above the ears. Patterson said medical records indicated that she had received several times the appropriate radiation dose, even more than the patients at Cedars-Sinai.
Hospital officials did not return calls seeking comment.
The FDA on Monday instructed hospitals across the country to review radiation dosing guidelines for CT perfusion scans. That includes training CT technologists to check the scanner display panel before starting a scan.
The FDA estimated that 150,000 CT brain perfusion scans are performed each year in the United States.
Under normal circumstances, the procedure uses more radiation than most other CT scans. It lasts 45 seconds as the patient is injected with an iodine solution and a rapid series of X-rays are taken to create a detailed picture of blood flow in the brain.
The radiation overdoses expose patients to a higher risk of several problems, the most serious of which would be developing a brain tumor, although radiation experts said the chance of that is remote. Because the risk from radiation is cumulative and cancer can take decades to develop, younger patients who received multiple scans face the greatest danger.
Shuren said the FDA is still investigating whether the overdoses resulted from human error, problems with the machines or a combination.
In a statement Monday, Arvind Gopalratnam, a spokesman for GE, said that in all cases, "there were no malfunctions or defects in any of the GE Healthcare equipment involved."
Charlene Jacobs, a spokeswoman for Toshiba, said the company is cooperating with FDA investigators.
The first indication that anything was wrong with the scans came in August when Cedars-Sinai discovered that it had accidentally exposed more than 200 patients to eight times the normal radiation for the procedure.
The overdoses went undetected for 18 months, even as many patients lost hair as a result.
In November, a similar problem was discovered at Glendale Adventist Medical Center. The hospital said that over a 10-month period, 10 patients received up to four times the normal level of radiation.
At both Cedars-Sinai and Glendale Adventist, the overdoses began after the hospitals had reprogrammed their machines to use a new protocol -- a set of computerized instructions -- to control the scans.
State investigators were unable to determine who authorized the changes at Cedars-Sinai or who programmed the machines. Officials at Glendale Adventist said a GE technician oversaw the changes there.