Assessment of Effective Dose and Organ Specific Dose at Pneumatic Reduction of Pediatric Ileocolic Intussusception

Abstract

Introduction: The purpose of this study was to estimate the radiation doses in children for pneumatic reduction of ileocolic intussusception on the basis of in-phantom dosimetry and conversion factor from dose-area product (DAP) to the effective dose and to identify patients or procedure-related factors contributing to higher radiation doses. Materials and Methods: The data of 68 children who underwent a total of 86 pneumatic reductions of ileocolic intussusception between December 2014 and December 2016 were retrospectively analyzed. The fluoroscopic time and DAP of pneumatic reduction were collected. The relationship between radiation dose and patients or procedural factors such as age, weight, body mass index (BMI), the time of procedure, radiologists experience, and presence of pathologic lead points were analyzed. A 5-year equivalent anthropomorphic phantom (ATOM CIRS 705 – D model) was exposed to mock pneumatic reduction procedures using mean, median, and maximum fluoroscopic times and DAP derived from clinical data. Organ-specific equivalent dose, effective dose, and conversion factors were calculated. For the direct comparison, additional radiation exposure to phantom using the routine abdominal radiography protocol was performed, and an effective dose was calculated. Results: An 88.4% (76/86) success rate per procedure and 91.2% (62/68) success rate per patient were achieved without any complications. The mean fluoroscopic time was 134.8 s (range: 24–1140 s) and the mean DAP was 49.06 cGycm2 (range: 1.7–420.4 cGycm2). The mean fluoroscopic time and DAP were significantly less in successful procedures compared to failed procedures (all Ps <0.001). The outcome of pneumatic reduction was the only independent factor for higher dosing (OR, 25.0

p=0.004). The mean and maximum estimated effective doses during the experimental study referenced with fluoroscopic time derived from clinical data collection were 0.25 and 2.15 mSv, which were equivalent to 4 to 36 abdominal radiographs. The derived conversion factor was 0.51 mSv/Gycm2. Conclusion: The mean effective dose for pneumatic reduction of intussusception was equivalent to 4 abdominal radiographs. Except for the outcome of reduction, there were no significant patient or procedural factors associated with radiation dose. Dose data and conversion factors derived from this study could be applied to estimate the effective dose for pneumatic reduction of pediatric ileocolic intussusception.