Fluoroscopy-controlled voiding cystourethrography in infants and children: are the radiation risks trivial?

The purpose of this study was to determine the gonadal dose, effective dose and relevant radiogenic risks associated with pediatric patients undergoing voiding cystourethrography (VCUG). Exposure parameters were monitored in 118 consecutive children undergoing VCUG. The entrance surface dose (ESD) was determined by thermoluminescent dosimeters (TLDs). For male patients, the gonadal dose was determined by TLDs attached on the anterior scrotum. For female patients, the gonadal dose was estimated by converting ESD to the ovarian dose. ESD-to-ovarian dose conversion factors were determined by thermoluminescence dosimetry and physical anthropomorphic phantoms representing newborn and 1-, 5- and 10-year-old individuals. The effective dose was estimated by using ESD and data obtained from the literature. The mean fluoroscopy time and number of radiographs during VCUG were 0.73 min and 2.3 for female and 0.91 min and 3.0 for male pediatric patients, respectively. The gonadal dose range was 0.34-5.17 mGy in boys and 0.36-2.57 mGy in girls. The corresponding ranges of effective dosage were 0.12-1.67 mSv and 0.15-1.45 mSv. Mean radiation risks for genetic anomalies and carcinogenesis following VCUG during childhood were estimated to be up to 15 per million and 125 per million, respectively. Radiation risks associated with pediatric patients undergoing VCUG should not be disregarded if such a procedure is to be justified adequately.