Procedure-specific CT Dose and Utilization Factors for CT-guided Interventional Procedures

Purpose: To present procedure-specific radiation dose metric distributions and define quantitative CT utilization factors for CT-guided interventional procedures. Materials and Methods: This single-center, retrospective study collected dictation reports and radiation dose data from 9143 consecutive CT-guided interventional procedures in adult patients from 2012 to 2017. Procedures were sorted into four major interventional categories: ablation, aspiration, biopsy, and drainage, each of which was further divided into subcategories. After exclusion, a total of 8213 procedures (4391 in men and 3822 in women) were divided into 21 subcategories. The mean patient age at examination for men was 62 years 6 15 (standard deviation; age range, 19-114 years), and for women it was 61 years 6 15 (age range, 19-113 years). Distributions of dose metrics and CT usage-related parameters were analyzed by category with descriptive statistic outcomes. Quantitative CT utilization factors (which measure average CT usage) for each interventional subcategory were derived by using total scan length, acquisition count, and number of images. Results: Interventional CT scans have distinctly different dose metric characteristics from diagnostic CT scans. Wide variations of dose metrics were observed among subcategories, even within the same major category. For the most frequently performed CT-guided interventional procedures within each major category, liver ablation, chest aspiration, liver biopsy, and single abdominal drainage, the median dose-length product was 2351, 657, 1175, and 1125 mGy.cm, respectively. Procedure-specific CT utilization factors ranged between 0.6 and 3.6. Conclusion: This study provides procedure-specific CT dose metric distributions and quantitative CT utilization factors on the basis of a large number of procedures and categorization of CT-guided interventional procedures. (c) RSNA, 2018