Author: Niki Fitousi, Stanley Thomas Fricke, Anna Romanyukha 👨🔬
Affiliation: Qaelum NV, Children's National Hospital 🌍
Purpose:
To identify opportunities for improvement through investigation of outliers in exam dose length product (DLP) and patients receiving high cumulative doses (CED), in the context of our “pediatric radiology dose reduction program”.
Methods:
Alerts for CEDs > 50 mSv and DLP values > 30% of age-based ACR Diagnostic Reference Level (DRL) were tabulated across 4820 pediatric exams using a dose management system.
CED values, total number of exams per patient, time between exams and exam types with the highest CED contribution were investigated.
DLP outliers were reviewed and evaluated by exam type and patient age. Extreme outliers (>2.3*DRL) were investigated.
Results:
In 14 cases CED exceeded 50 mSv. Ranges for CED, number of exams per patient, and mean intervals between exams were 53-191 mSv, 2-24 exams, and 1-75 days, respectively. The most common CED contributors were CT Angio Abdomen (N=7) and PET Whole Body (N=5), exceeding expected mean effective doses for these exams by 55% and 71%, respectively.
79 DLP outliers were identified (1.6% of exams). The most common DLP outlier groups were chest without contrast (N=27) and abdomen and pelvis with contrast (N=21). Of the outliers 54% and 32% were in patient age groups of <1 year and 1-4 years, respectively. 38% of the outliers were considered reasonable, 16% were due to incorrect study description, 14% were due to patient size, and 10% were due to repeated scans. Highest outlier mean DLPs were due to repeated scans (DRL >71%). Extreme outliers: 7 of 9 were due to an incorrect study description entry.
Conclusion:
Few CED and exam DLP outliers were found, indicating good practice. Outlier review identified deviations from reference dose levels and common deviation causes, and helped target exam types and specific patient-age groups for future optimization/dose reduction efforts.