December 2012

Dose Specifics
By Jim Knaub
Radiology Today
Vol. 13 No. 12 P. 3

Alexander Bankier, MD, PhD, and Herbert Kressel, MD, believe the term “low dose” exceeds their meaningless use criteria, and they want it out of Radiology, the journal they edit together. Bankier told writer Beth Orenstein that what could have been considered low dose a decade ago would not be seen that way today—even if the term ever had been clearly defined along the way. That lack of meaning is a problem in the data-driven world of science—as much as anything, low dose is a vague marketing term, making it a good thing to pare from journal content.

Going forward, as discussed in Orenstein’s article on page 18, Bankier and Kressel would like to mothball the term and report four quantifiable metrics: CT dose index (CTDIvol), dose length product (DLP), effective diameter, and size-specific dose estimate. That makes more sense, but as you’ll also read in this issue, it’s not the only dose-reduction and reporting issue that requires some adjustment.

In a Radiology Today interview, California-based healthcare consultant Shawn McKenzie discusses dose recording and reporting in the context of that state’s new dose law. California now requires that CTDIvol and DLP be included in the radiology report or attached to it for every CT scan. The law also mandates reporting to the state, referring physician, and patient if certain radiation thresholds—50-mSv effective dose or 500-mSv organ, tissue, or skin dose—are exceeded in an individual exam. There also are requirements related to therapeutic radiation. But as McKenzie points out in the interview on page 22, the CTDIvol and DLP now required in reports do not answer the question of whether the state-mandated threshold is met; that requires a calculation by a medical physicist.

The California recording and reporting law is hardly the first case of good intentions not being met on the first legal try. The current California law gives no consideration to aggregate dose. McKenzie expects the law to evolve—if not in California, in other states or nationally—because he senses that the industry rightly thinks it is time to better address the issue.

In the meantime, McKenzie says the ACR is helping with guidelines regarding what CTDIvol and DLP levels suggest that you might have a reportable event and it’s a good idea to call your physicist. It’s not an ideal solution, but it’s a reasonable workaround to keep imaging organizations in compliance.

Dose-reporting laws will likely expand beyond California. Gathering data and improving the system both matter and legislators will refine the laws. Better monitoring of radiation dose just makes sense, and organizations that give it serious thought will benefit.

Enjoy the issue.