Assessing trends in patients undergoing recurrent CT examinations and cumulative doses.

PURPOSE: Recent research has enhanced our understanding of the number of patients receiving relatively high radiation doses (≥100 mSv) through recurrent CT examinations. However, there is a paucity of information on temporal trends. This study elucidates these trends over the past 11 years. METHODS: We retrieved data on CT exams conducted from 2013 to 2023 from our hospital's dose-management system. We analyzed the number of patients undergoing recurrent CT examinations, calculated the median cumulative effective dose (CED), and assessed the frequency of patients receiving doses of ≥ 50 mSv and ≥ 100 mSv. Generalized linear models that accounted for autocorrelation via Newey-West covariance estimates and non-linearities due to the COVID-19 pandemic were employed to quantify temporal trends. RESULTS: Among 403,997 patients in 11 years, 46.3 % had 1 CT exam, 53.7 % received ≥ 2 exams, 20.3 % received ≥ 5 exams, and 8.3 % had ≥ 10 exams, with 6.6 % having CEDs ≥ 100 mSv. The rate of recurrent exams decreased post-2020 (incident rate ratio, IRR: 1.029, 95 % CI 1.025, 1.033). The median CED increased post-2020 relative to pre-2020 (difference in annual changes: -0.102, 95 % CI -0.119, -0.085). Patients with new annual doses ≥ 100 mSv decreased post-pandemic (IRR: 0.976, 95 % CI 0.955, 0.997). CONCLUSIONS: In this study examining temporal trends, the percentage of patients undergoing multiple CT examinations has changed since 2020, with a shift from an increasing to a decreasing trend in those receiving cumulative doses ≥ 100 mSv per year. This suggests an alteration in imaging practices or patient demographics since 2020, providing valuable insights to inform policymaking.

Duke Scholars

Author Madan Mohan Rehani Radiology