Abstract
1564
Background: The pursuit of lowering radiation exposure from medical imaging has led to increasing adoption of radiation-saving practices (RSP), a set of protocol- and/ or camera-based practices that aim to optimize patients’ radiation dose with myocardial perfusion imaging (MPI) without compromising the diagnostic quality of studies. The extent to which patients’ radiation dose vary between sites with and without access to RSP has not been examined.
Methods: Using the nuclear laboratory database at Saint Luke’s Mid America Heart Institute (Kansas City, MO), we identified consecutive patients referred for clinically-indicated MPIs between 1/10 and 12/16. Patient demographics and imaging protocols were recorded at the time of study performance. Rest/ stress PET, stress-only SPECT and low-dose rest/stress SPECT using solid-state detector cameras were considered RSP. Patients were divided based on whether they were imaged at sites with (RSP+) or without access to RSP (RSP-). Patients were age-, gender-, BMI- and year-matched (5:1) between the 2 groups. Mean effective radiation dose (E) was calculated for each group and between-group comparison was done using matched-sample t-test. Results: During the study period, 15,065 patients who underwent MPI at RSP+ sites were matched to 3,013 patients imaged at RSP- sites (53.2% females, mean age 63.7 ± 12.1 yrs, BMI 33 ± 7). E declined significantly between 2010-2016 at sites with and without RSP (P<0.0001 for both trends). Furthermore, RSP+ sites consistently had a lower mean E compared to RSP- sites (P<0.0001 for all time points, Figure), with a 51-63% relative reduction in E with RSP use E. Conclusion: In this matched comparison between sites with and without access to RSP, integration of RSP significantly reduced patients’ radiation exposure. Efforts to disseminate RSP protocols may improve the safety of diagnostic imaging with MPI.