Teaching Responsible Conduct of Research (RCR): A Resource Guide for Professional Science Master’s Degree Programs
Case Studies from Medical Physics
Case: CT Scanner Patient Overdose Incident
Discipline:
Medical Physics
Title:
CT Scanner Patient Overdose Incident
Author:
Steven Goetsch, Ph.D.
Edited by:
Usha Sinha, Ph.D.
A major highly respected California medical center begins to receive complaints from patients
scanned in their radiology department of unexpected hair loss. Investigation reveals that all patients
received a CT scan for suspected stroke. The hospital physicist reproduces the scan conditions and
discovers that the patients were exposed to eight times the dose considered acceptable, and enough
to cause epilation. Within days a newspaper publishes a story about it and soon 260 patients were
confirmed to have been over-exposed. The hospital had wanted to avoid a press release and keep
everything “low key” but now the story is out. Administration and hospital attorneys drafted a
carefully worded letter to be sent to patients suggesting there might be a problem and they should
contact their referring physician “who would know best.”. The referring physicians, mostly
neurologists, have no expert knowledge about CT scans and are enraged to be blamed for the
situation and being asked by the hospital to deal with scared, angry patients.
The medical physicist also determines that these incidents occurred after a new protocol was
introduced. The specific protocol was requested by a new radiologist with the vendor technical
support engineer and the CT technologist involved in actual implementation. The medical physicist
knew of the introduction of the new protocol and quickly skimmed through the settings, but at the
time did not perform any tests to make sure that dose was in acceptable range. Mr. T was then a
new intern physicist from a local academic institution training in CT. Mr T was zealous about his
new position and took the responsibility of the physicist seriously. He noticed that no physicist
check was performed and enquired of the lead medical physicist. Mr. T’s suggestions were swept
aside: the chief physicist claimed that the vendor support engineer was experienced, knew how to set
protocols, and that the new radiologist was very particular about having the protocol set that way.
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Teaching Responsible Conduct of Research (RCR): A Resource Guide for Professional Science Master’s Degree Programs
Mr. T was intimidated by the chief physicist and does not pursue it any further even when he notices
that very thin slices are being acquired, which would mean high doses.
Other hospitals in other parts of the country later report scattered similar instances and more than
one CT scanner manufacturer is involved. Plaintiff lawyers soon appear and sign up clients for a
class action lawsuit against the very wealthy hospital. The State of California Radiologic Health
Branch begins an investigation with local experts from major academic medical centers to find the
cause, but cannot cite any violation of state laws or even guidelines. Within months a major new
piece of radiation regulation is passed by the California legislature and signed into law by the
governor.
Teaching Questions:
1. What went wrong? Was the manufacturer to blame? Should the radiation technologist
have “known better”?
2. Was the hospital medical physicist to blame? Should he or she have done QA measurements
that would have revealed this situation?
3. As the intern, did Mr. T have any other option after the chief medical physicist brushed away
his suggestions? Could he have conducted the QA tests himself without the medical
physicists explicit permission?
4. Should Mr. T have been more alert to the ‘thin slice’ situation and performed the dose
calculations to confirm if they met regulations or not? Or alerted someone in the
organization?
5. Who should the intern have approached after he got nowhere with the chief medical
physicist? What is the chain of command in a hospital setting that the intern has recourse to:
e,g, the Chief Technologist, the radiologist who was using the protocol, the Radiation Safety
Officer?
6. Should the intern have consulted with the faculty at his/her academic institution?
7. How should the hospital have handled this situation? Is “stonewalling” a good idea? Is it
best to “contain” the situation or be bluntly honest?
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Teaching Responsible Conduct of Research (RCR): A Resource Guide for Professional Science Master’s Degree Programs
8. Should the manufacturer have explicitly warned the hospital that their CT scanner was
powerful enough to deliver a dose comparable to a cancer therapy dose just from a
diagnostic study? Were the radiation technologists to blame for not knowing the
consequences of such prolonged scans? Were the radiologists to blame for forgetting their
radiation biology training and demanding many consecutive high dose scans?
9. Why is there never enough time to do it right but always enough time to do it over?
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