Objective: To quantify and evaluate radiation dose for pediatric patients from age of one day to 15 years that underwent VCUG according to the protocol used at King Chulalongkorn Memorial Hospital.

Materials and Methods: The data of 191 consecutive pediatric patients that underwent VCUG according to the protocol used at King Chulalongkorn Memorial Hospital, including demographic data, entrance skin dose (ESD), dose-area product (DAP), the fluoroscopy time, and the number of the radiographic acquisition for each patient between January 2014 and October 2016 was recorded. The data was classified into two groups according to positive or negative vesicoureteral reflux (VUR), and to four stratifications based on age.

Results: The mean ESD, DAP, and effective doses of 191 children were 6.44 mGy, 82.97 cGy·cm², and 0.17 mSv, respectively. The local third-quartile diagnostic reference levels (DRLs) levels in each age groups were calculated as 34.73, 54.87, 142.71, and 254.46 cGy.cm² in the age of 0 to 1, more than 1 to 5, more than 5 to 10, and more than 10 to 15 years, respectively. The median number of the radiographic acquisition was 2. The average fluoroscopic time during examination was 87.80 seconds. The DAPs of male and female patients were not significantly different. The patients with VUR had significantly higher DAP than the patients without VUR.

Conclusion: The means of DAP values in the present study and in each age stratification were lower than those reported by other authors, except in age group 0 to 1 year. The local DRL values in some age groups were higher than in another study in Thailand and ICRP 2011. Radiologists should be aware of radiation dose used and try to lower the radiation dose in the pediatric patients.

Keywords: Voiding cystourethrography, Fluoroscopy, Radiation dose, Effective dose, Children