Hundreds of radiation overdoses went undetected for 18 months

It took 18 months before someone at Cedars-Sinai Medical Center in Los Angeles noticed that hundreds of patients had received more than eight times the normal dose of radiation. The error was detected only after a patient complained of losing hair shortly after receiving a scan.

"Somebody should have noticed. But nobody did--everybody trusted the machines," the Los Angeles Times declared.  

The problem traces back to February 2008, when the organization began using a new protocol for a specialized type of scan that would offer physicians more data about disruptions in blood flow to brain tissue. At the time, the machine was reset to override pre-programmed instructions that came with the scanner, which then locked in the higher dose. Although the machine was used for different scans, the 206 patients who received a CT brain perfusion were the only patients affected.

"There was a misunderstanding about an embedded default setting applied by the machine...," hospital officials said in a written statement. "As a result, the use of this protocol resulted in a higher than expected amount of radiation."

The mistake wasn't discovered until August 2009, 18 months later, after a stroke patient reported losing his hair following a scan. Since then, the hospital has contacted every patient who had the brain perfusion scans to inform them of the mistake. It discovered that 40 percent had experienced patchy hair loss.

The reset error prompted the Food and Drug Administration to warn hospitals last week to check their CT protocols. And yet, medical radiation experts say it's not uncommon for radiologists to override pre-programmed instructions.

Hospital officials said they have since "added double-checks to our process whenever a protocol is changed." But why those safety measures weren't already in place is a question many experts--and patients--are asking.

For more on the story:
- see the LA Times article