A rapid-fire series of radiation-related events, beginning in mid-2009 and continuing into 2010, culminated in the recent bombshell that the FDA would begin regulating medical radiation. Both the industry and the specialty continue to reverberate.
Although these recent events were accompanied, and possibly fanned, by some confused and histrionic reporting in the popular press, inevitability is written all over this development. Radiation safety was radiology’s ticking time bomb, and radiology was not doing enough to address the issues.
In response to the finding of the National Council on Radiation Protection and Measurements (NCRPM) 1 that per-capita radiation exposure had increased fivefold between 1980 and 2006 (when half the cumulative dose could be attributed to CT), it was not enough to say that the benefits of medical imaging outweigh any possible negative effects.
Though estimations of the risk of medical imaging were extrapolated from the atomic-bomb survivors and their much higher exposures, it was not enough to point out the flaws in the linearity concept. Radiology must apply some science to these questions.
The good news is that steps are being taken that will enable that to happen. Several weeks before the FDA’s announcement, Neumann and Bluemke 2 announced that Radiology and Imaging Sciences at the National Institutes of Health (NIH) Clinical Center has developed a radiation reporting policy that will be instituted in cooperation with major equipment vendors of CT and PET/CT, with the ultimate goal of incorporating radiation-dose exposure into a patient’s electronic health record (EHR). NIH will work with equipment vendors to arrive at a standardized reporting algorithm to enable dose data to be entered into an image’s DICOM header and then extracted for storage, either in the RIS or in the hospital-based EHR.
Neumann and Bluemke point out that these steps, in and of themselves, are insufficient to determine the radiation risks that may or may not be associated with medical imaging. They are necessary, however, for the accumulation of dose data from hundreds of thousands of patients, over many years, that will be required. If the Obama administration’s efforts to spur widespread adoption of EHRs prevail, and if the dose data are entered therein, this would produce a large dataset for studies of the long-term effects of medical imaging.
The time clearly is ripe for such investigations. Farooki 3 writes about epigenetics (that mildly unnerving branch of science that probes changes in the phenotype caused by mechanisms other than DNA alteration), a field that Farooki says may have a greater role in medicine than genetics itself. It is unsettling indeed to consider the damage inflicted on oneself by what one did or does not do to one’s body, without considering the effects on our children and our children’s children. Farooki notes that the NIH has earmarked $190 million for epigenetic research over five years, and suggests that we need to understand the epigenetic effects of radiation exposure.
A wide-ranging FDA initiative 4 announced February 9 is intended to promote the safe use of medical imaging, support informed clinical decisions, and increase patient awareness. As described, these ambitions will leave few corners of the specialty untouched.
Diagnostic reference levels (or dose reference values) for imaging procedures will no longer be the provenance of the department physicist, but the domain of everyone from technologists to radiologists to department administrators and leaders. Citing the efforts of the ACR® and the NCRPM, the FDA urges the development and use of dose reference levels; where there are no national standards, it suggests that facilities develop these locally.
The FDA may require CT and fluoroscopic devices to display, record, and transmit radiation dose and to use default parameter settings that optimize radiation dose (or that emit alerts when an exam’s dose exceeds a specified reference level). The FDA may also require devices to record radiation dose automatically in a DICOM structured report and to transmit this information to the EHR or to a dose registry. Additional training for users is also a likely requirement. The FDA intends to hold a public meeting on March 30–31, 2010, to solicit input on what requirements to establish.
To support referring physicians in their clinical decisions, the development of appropriate-use criteria for CT, fluoroscopy,