In October 2009, the Food and Drug Administration issued an alert to all radiologists, emergency room physicians and others involved in doing CT scans. (A CT scan is a Computed Tomography scan, which is a medical test that uses a computer and x-ray machine to take accurate and detailed images of the inside of the body.) A report had been received from a major medical center that their CT scanner had been improperly set for 18 months, meaning that hundreds of patients received overdoses to their heads of six to eight times the intended dose of x-rays. The equipment was being used to do brain scans for the diagnosis of strokes.

The error was noted when a patient complained of patchy hair loss. An investigation determined that other patients also had hair loss and had experienced a sunburn-like reddening of the skin, neither of which should have occurred after normal treatment.

Two hundred and six patients had to be notified of the error and given additional information to follow up on their overexposure to radiation.

The FDA noted that this was an extreme instance of overdose, where patients received such an overdose that some of them experienced symptoms. In a case of a lesser overdose, there might not be symptoms. In any event, radiation overdoses are normally slow to show their effects, meaning that some patients may not connect the cause and the effects.

Unfortunately, this incident is not the only one on record. The FDA Adverse Effect database contains other reports of operator error or software failure that caused the administration of nearly six times the intended dose in one case. A search of the Internet shows other incidents reported by individuals. The conclusion that can be drawn is that this is not an isolated incident. The FDA notes that there has been an increased utilization of CT in recent years and that the new CT machines have a higher dose-rate capability. Both these factors increase the chances that more people may experience overdoses.

For your safety, ask the technician to double-check the settings for a treatment for yourself or a loved one. Then, don’t be afraid to ask to have a second person verify the settings before treatment starts. This is standard procedure in some institutions. The result of accuracy is a minimal dose of radiation for treatment or scanning purposes. And a maximum dose of safety.

Source: Food and Drug Administration, MedWatch, “CT Brain Perfusion Scans Safety Investigation: Initial Notification,” 10/09/2009, http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm186105.htm

Source: Food and Drug Administration, MAUDE Adverse Effect report, 07/25/2005, http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/Detail.CFM?MDRFOI__ID=751476,

Source: Food and Drug Administration, MAUDE Adverse Effect report, 9/15/2006, http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfMAUDE/Detail.CFM?MDRFOI__ID=787084

Source: Food and Drug Administration, “FDA Preliminary Public Health Notification: Possible Malfunction of Electronic Medical Devices Caused by Computed Tomography (CT) Scanning,” July 14, 2008, http://www.fda.gov/MedicalDevices/Safety/AlertsandNotices/PublicHealthNotifications/ucm061994.htm