The Food & Drug Administration released interim guidance on radiation exposure during CT scans and said the agency is looking for more possible cases of overexposure, after a report in October that more than 200 patients were exposed to excess doses of the toxic particles.
The exposure cases at Cedars-Sinai Medical Center in Los Angeles, which apparently persisted unchecked for more than 18 months before patient complaints led to the discovery, set off a broader investigation at the FDA. In its examination, the federal watchdog agency said it has found 50 more cases of people exposed to, in some cases, more than eight times the expected level of radiation to date. On a conference call with reporters, acting Centers for Devices and Radiological Health chief Dr. Jeffrey Shuren said machines made by GE Healthcare and Toshiba were involved in the exposure cases. However, officials have not made a determination about whether the machines or human error were to blame.
While the agency says the investigation is still ongoing, it released new standard operating procedures for all imaging facilities, radiologists and radiologic technologists:
- Facilities assess whether patients who underwent CT perfusion scans received excess radiation.
- Facilities review their radiation dosing protocols for all CT perfusion studies to ensure that the correct dosing is planned for each study.
- Facilities implement quality control procedures to ensure that dosing protocols are followed every time and the planned amount of radiation is administered.
- Radiologic technologists check the CT scanner display panel before performing a study to make sure the amount of radiation to be delivered is at the appropriate level for the individual patient.
- If more than one study is performed on a patient during one imaging session, practitioners should adjust the dose of radiation so it is appropriate for each study.