Optimizing Radiation Doses for Computed Tomography Across Institutions

Abstract

IMPORTANCE Radiation doses for computed tomography (CT) vary substantially across institutions. OBJECTIVE To assess the impact of institutional-level audit and collaborative efforts to share best practices on CT radiation doses across 5 University of California (UC) medical centers. DESIGN, SETTING, AND PARTICIPANTS In this before/after interventional study, we prospectively collected radiation dose metrics on all diagnostic CT examinations performed between October 1, 2013, and December 31, 2014, at 5 medical centers. Using data from January to March (baseline), we created audit reports detailing the distribution of radiation dose metrics for chest, abdomen, and head CT scans. In April, we shared reports with the medical centers and invited radiology professionals from the centers to a 1.5-day in-person meeting to review reports and share best practices. MAIN OUTCOMES AND MEASURES We calculated changes in mean effective dose 12 weeks before and after the audits and meeting, excluding a 12-week implementation period when medical centers could make changes. We compared proportions of examinations exceeding previously published benchmarks at baseline and following the audit and meeting, and calculated changes in proportion of examinations exceeding benchmarks. RESULTS Of 158 274 diagnostic CT scans performed in the study period, 29 594 CT scans were performed in the 3 months before and 32 839 CT scans were performed 12 to 24 weeks after the audit and meeting. Reductions in mean effective dose were considerable for chest and abdomen. Mean effective dose for chest CT decreased from 13.2 to 10.7 mSv (18.9% reduction; 95% CI, 18.0%-19.8%). Reductions at individual medical centers ranged from 3.8% to 23.5%. The mean effective dose for abdominal CT decreased from 20.0 to 15.0 mSv (25.0% reduction; 95% CI, 24.3%-25.8%). Reductions at individual medical centers ranged from 10.8% to 34.7%. The number of CT scans that had an effective dose measurement that exceeded benchmarks was reduced considerably by 48% and 54% for chest and abdomen, respectively. After the audit and meeting, head CT doses varied less, although some institutions increased and some decreased mean head CT doses and the proportion above benchmarks. CONCLUSIONS AND RELEVANCE Reviewing institutional doses and sharing dose-optimization best practices resulted in lower radiation doses for chest and abdominal CT and more consistent doses for head CT.

Outcompeting p53-Mutant Cells in the Normal Esophagus by Redox Manipulation

“…IR exposure led to a dose-dependent increase in double-strand breaks (DSBs) and a decrease in proliferation 24 h after exposure (Figures S2A–S2J). We selected 50 mGy, equivalent to 3–4 computed tomography (CT) scans, for further study (Demb et al., 2017). This dose resulted in an average of one DSB in every 5 cells and did not change proliferation marker expression 24 h after irradiation or induce apoptosis (Figures S2C, S2D, S2G–S2J, and S2K–S2M).…”

“…Insight into normal and mutant cell behavior in EE has come from genetic lineage tracing studies in transgenic mice (Figure S1; Alcolea et al., 2014, Alcolea and Jones, 2013, Doupé et al., 2012, Frede et al., 2016). Here we apply this technique to test whether the selection of p53 mutant clones is altered by oxidative stress resulting from low-dose ionizing radiation (LDIR) with doses similar to those from medical imaging and environmental contamination (Demb et al., 2017, Hasegawa et al., 2015). We find that LDIR exposure promotes the expansion of p53 mutant clones.…”

International variation in radiation dose for computed tomography examinations: prospective cohort study

“…Education and collaboration in setting standards could offer the largest effect on optimizing dose. 41 42 Choosing appropriate CT protocol parameters might be less complex than widely believed. Institutions with lower doses shared scanning approaches.…”

CT is still not a low‐dose imaging modality

“…CT dose for a defined level of diagnostic information has gone down substantially . Many publications have assessed how different technologies or techniques have helped to reduce the dose in a single CT examination while maintaining the same level of noise in the image or how and how much dose reduction could be achieved for the same CT examination without loss of clinical utility.…”