Radiation Dose Monitoring for Fluoroscopically Guided Interventional Procedures: Effect on Patient Radiation Exposure

Purpose: To analyze the clinical effect of continuous dose monitoring and patient follow-up for fluoroscopically guided vascular interventional procedures over 8 years. Materials and Methods: In this retrospective study, an in-house semiautomated system was developed for fluoroscopic dose monitoring. The quarterly number of procedures from January 2010 to December 2017 was analyzed with count time series to estimate quarterly change rate. Technologists recorded four dose surrogates in custom fields of institutional dictation software through a Web interface. Radiation doses were transferred automatically to the radiology report and a centralized dose database when the radiologist initiated procedure dictation. A medical physicist reported weekly on procedures with air kerma at the reference point (K-a,K-r) of 2 Gy or higher to a division-designated radiologist and hospital radiation safety committee who required the attending radiologist to set up follow-up appointments for patients who underwent procedures with a K-a,K-r greater than or equal to 5 Gy. Results: There were a total of 41 585 procedures; 1553 (3.7%) procedures had a K-a,K-r of 2-5 Gy. Among 240 procedures with K-a,K-r greater than 5 Gy, 22 had K-a,K-r greater than 9 Gy. The percentage of high K-a,K-r procedures decreased over time, going from 5.9% in 2010 to 2.0% in 2017 for procedures with K-a,K-r of 2-5 Gy and from 1.0% in 2010 to 0.13% in 2017 for procedures with K-a,K-r greater than or equal to 5 Gy. Relative reduction per quarter was approximately 2.7% (95% confidence interval: 1.5%, 3.8%) for K-a,K-r of 2-5 Gy and 4.5% (95% confidence interval: 1.5%, 7.6%) for K-a,K-r greater than or equal to 5 Gy. Conclusion: Eight-year temporal trends show three-to eightfold reduction in the number of high-dose procedures. (C) RSNA, 2019