Evolving operator practices reduced patient radiation dose in Interventional Cardiology: Trends in a single center

Abstract

Background: This retrospective study addresses the role of operator and fluoroscopy equipment in reducing patient radiation exposure in the Cath lab.

Methods: Data from 99,400 procedures performed in our institution between 2007 and 2019 were reviewed. Dosimetric parameters included reference point air kerma (K_a,r), Kerma Area Product (P_KA), fluoroscopic time, and contrast volume. Results are characterized by their 50^th and 99^th percentiles. Data from a subset of fluoroscopes that were in continuous use and a subset of operators who used the same "continuous" fluoroscope in every year of the study were also analyzed.

Results: For all procedures, median K_a,r declined by 63%, from 1.5 to 0.5 Gy; 99^th percentiles declined by 44%, from 8.6 to 4.8 Gy. For the three "continuous fluoroscopes" median K_a,r declined by 60% from 1.6 to 0.6 Gy; 99th percentile by 52% from 9.1 to 4.4 Gy. The all-procedure median contrast volume declined by 53%, from 150 to 70 ml; 99th percentile by 42% from 600 to 350 ml. The all-procedure median fluoroscopy time declined by 2%; the 99th percentile increased by 32%. In the continuous subset, median fluoroscopy time declined by 20%; 99^th percentile increased by 5%. For the operator's subset, the median K_a,r declined by 43% (p=0.0362); the 99^th percentile decreased by 22% (p=0.0481). Substantial radiation dose procedures decreased from 7% to 0.8% of the procedure volume.

Conclusions: There was a significant reduction in patient radiation (K_a,r and P_KA) and contrast volume during the study period driven by systematic and operator practice changes.

Keywords: Cardiac catheterization; fluoroscopy; kerma area product; patient radiation dose; reference air kerma.