Patient Radiation Doses in Interventional Radiology Procedures: Comparison of Fluoroscopy Dose Indices between the American College of Radiology Dose Index Registry-Fluoroscopy Pilot and the Radiation Doses in Interventional Radiology Study

Purpose To compare radiation dose index distributions for fluoroscopically guided interventions in interventional radiology from the American College of Radiology (ACR) Fluoroscopy Dose Index Registry (DIR-Fluoro) pilot to those from the Radiation Doses in Interventional Radiology (RAD-IR) study. Materials and Methods Individual and grouped ACR Common identification numbers (procedure types) from the DIR-Fluoro pilot were matched to procedure types in the RAD-IR study. Fifteen comparisons were made. Distribution parameters, including the 10th, 25th, 50th, 75th, and 95th percentiles, were compared for fluoroscopy time (FT), cumulative air kerma (K a,r ), and kerma area product ( P KA ). Two derived indices were computed using median dose indices. The procedure-averaged reference air kerma rate ( K a , r ¯ ) was computed as K a,r / FT. The procedure-averaged x-ray field size at the reference point (A r ) was computed as P KA / (K a,r × 1,000). Results The median FT was equally likely to be higher or lower in the DIR-Fluoro pilot as it was in the RAD-IR study, whereas the maximum FT was almost twice as likely to be higher in the DIR-Fluoro pilot than it was in the RAD-IR study. The median K a,r was lower in the DIR-Fluoro pilot for all procedures, as was median P KA . The maximum K a,r and P KA were more often higher in the DIR-Fluoro pilot than in the RAD-IR study. K a , r ¯ followed the same pattern as K a,r , whereas A r was often greater in DIR-Fluoro. Conclusions The median dose indices have decreased since the RAD-IR study. The typical K a,r rates are lower, a result of the use of lower default dose rates. However, opportunities for quality improvement exist, including renewed focus on tight collimation of the imaging field of view.