Dose length product to effective dose coefficients in children

Abstract

Background The most accurate method for estimating effective dose (the most widely understood metric for tracking patient radiation exposure) from computed tomography (CT) requires time-intensive Monte Carlo simulation. A simpler method multiplies a scalar coefficient by the widely available scanner-reported dose length product (DLP) to estimate effective dose. Objective Develop pediatric effective dose coefficients and assess their agreement with Monte Carlo simulation. Materials and methods Multicenter, population-based sample of 128,397 pediatric diagnostic CT scans prospectively assembled in 2015–2020 from the University of California San Francisco International CT Dose Registry and the University of Florida library of highly realistic hybrid computational phantoms. We generated effective dose coefficients for seven body regions, stratified by patient age, diameter, and scanner manufacturer. We applied the new coefficients to DLPs to calculate effective doses and assessed their correlations with Monte Carlo radiation transport-generated effective doses. Results The reported effective dose coefficients, generally higher than previous studies, varied by body region and decreased in magnitude with increasing age. Coefficients were approximately 4 to 13-fold higher (across body regions) for patients <1 year old compared with patients 15–21 years old. For example, head CT (54% of scans) dose coefficients decreased from 0.039 to 0.003 mSv/mGy-cm in patients <1 year old vs. 15–21 years old. There were minimal differences by manufacturer. Using age-based conversion coefficients to estimate effective dose produced moderate to strong correlations with Monte Carlo results (Pearson correlations 0.52–0.80 across body regions). Conclusions New pediatric effective dose coefficients update existing literature and can be used to easily estimate effective dose using scanner-reported DLP.

Age-Dependent Changes in Effective Dose in Pediatric Brain CT: Comparisons of Estimation Methods

“…Each facility determines median values of CTDIvol and DLP recorded in clinical practice for each age group, and the 75th percentile values of the medians reported from many facilities are defined as the DRLs. In this study, we grouped patients into 0-, 1–4-, 5–9-, and 10–14-year age groups [ 3 , 4 ] and determined the median DLP and ED for each age group. The median DLP values were lower than the DRL values in our country [ 20 ].…”

“…Computed tomography (CT) delivers relatively high radiation doses, and the potentially detrimental effects of CT radiation exposure are a significant concern in modern medicine [ 1 ]. Evaluation of brain abnormalities is the most common indication of CT in children [ 2 , 3 , 4 ]. In the dose survey for pediatric CT in the USA, 52.6% of the analyzed examinations were brain CT excluding the scans of the sinus and maxillofacial area (4.3%, 2.8%, 7.0%, and 38.5% for 0, 1, 2–5, and 6–18 years, respectively) [ 3 ].…”

Life Time Attributable Cancer Risk Estimated Using Scanner Reported Dose Length Product during Chest Computed Tomography Imaging in Young Children

“…Multiplying the universally reported DLP by scalar coefficient offers a simple, rapid method for clinicians to estimate ED, which can be included in the medical record and tracked over time [18].…”