Treatment and evaluation of vesicoureteric reflux (VUR) become more elaborate and differentiated. Still, reliable diagnostics are an essential part of risk adapted, individually tailored management. Although radiation free voiding cystourethrography (VCUG) by use of contrast enhances ultrasound (CEUS) is slowly gaining popularity, most of the methods used for evaluation of VUR use ionizing radiation.
Fluoroscopic or radiologic VCUG represents the gold-standard method for evaluation of VUR while direct (and to a very limited extent indirect) isotope cryptographies (DIC / IIC) are mainly used for follow-up examinations.
Even more than in adults, limiting radiation exposure is an issue in children. Not only is radiation exposure more relevant the earlier it is afflicted, there seem to be also cytogenetic factors that render children more vulnerable to sequelae caused by exposure to ionizing radiation. In practical application of the ALARA (“as low as reasonably achievable”) principle, DIC was used despite its shortcomings, which are its lack of anatomical detail (urethra, calyceal anatomy, intrarenal reflux) mainly for follow-up examinations in order to limit radiation exposure.
The assumption, that DIC confers less radiation burden compared to radiologic or fluoroscopic VCUG, however, is based on antiquated data and relies on measurements using outdated radiological equipment and techniques. Through technical advances including grid controlled, pulsed digital fluoroscopy, very high quality images can be acquired using less radiation than only ten to fifteen years ago.
Therefore we reevaluated the radiation burden of fluoroscopic VCUG and DIC and found that using modern equipment and a radiation-saving protocol, conventional fluoroscopic VCUG confers less radiation burden compared to DIC, contrary to common beliefs.
Written by:
Bernhard Haid, MD, FEBU
Department for Pediatric Urology, Hospital of the Sisters of Charity, Linz, Austria