Assessment of Regional Pediatric Computed Tomography Dose Indices in Tamil Nadu

The aim of this article is to assess Tamil Nadu pediatric computed tomography (CT) diagnostic reference levels (DRLs) by collecting radiation dose data for the most commonly performed CT examinations. This work was performed for thirty CT scanners installed in various parts of the Tamil Nadu region. The patient cohort was divided into two age groups: <1 year, and 1-5 years. CT dose indices were measured using a 10 cm³ pencil ion chamber with pediatric head and body polymethyl methacrylate phantoms. Dose data such as volumetric CT dose index (CTDI_v) and dose length product (DLP) on a minimum of twenty average-sized pediatric patients in each category were recorded to calculate a mean site CTDI_v and DLP value. The rounded 75^th percentile was used to calculate a pediatric DRL for each hospital, and then region by compiling all results. Data were collected for 3600 pediatric patients. Pediatric CT DRL for two age groups: <1 year (CTDI_v and DLP of head [20 mGy, 352 mGy.cm], chest [7 mGy, 120 mGy.cm] and abdomen [12 mGy, 252 mGy.cm]), and 1-5 years (CTDI_v and DLP of head [38 mGy, 505 mGy.cm], chest [8 mGy, 132 mGy.cm] and abdomen [14 mGy, 270 mGy.cm]) for select procedures have been calculated. Proposed pediatric DRLs of CTDI_v and DLP for head procedure were lower, and for chest and abdomen procedures were higher than European pediatric DRLs for both age groups.