Radiation dose measurement and risk estimation for paediatric patients undergoing micturating cystourethrography

Abstract

Micturating cystourethrography (MCU) is considered to be the gold-standard method used to detect and grade vesicoureteric reflux (VUR) and show urethral and bladder abnormalities. It accounts for 30-50% of all fluoroscopic examinations in children. Therefore, it is crucial to define and optimize the radiation dose received by a child during MCU examination, taking into account that children have a higher risk of developing radiation-induced cancer than adults. This study aims to quantify and evaluate, by means of thermoluminescence dosimetry (TLD), the radiation dose to the newborn and paediatric populations undergoing MCU using fluoroscopic imaging. Evaluation of entrance surface dose (ESD), organ and surface dose to specific radiosensitive organs was carried out. Furthermore, the surface dose to the co-patient, i.e. individuals helping in the support, care and comfort of the children during the examination, was evaluated in order to estimate the level of risk. 52 patients with mean age of 0.36 years who had undergone MCU using digital fluoroscopy were studied. ESD, surface doses to thyroid, testes/ovaries and co-patients were measured with TLDs. MCU with digital equipment and fluoroscopy-captured image technique can reduce the radiation dose by approximately 50% while still obtaining the necessary diagnostic information. Radiographic exposures were made in cases of the presence of reflux or of the difficulty in evaluating a finding. The radiation surface doses to the thyroid and testes are relatively low, whereas the radiation dose to the co-patient is negligible. The risks associated with MCU for patients and co-patients are negligible. The results of this study provide baseline data to establish reference dose levels for MCU examination in very young patients.

Recurrent urinary tract infections in young children: role of DMSA scintigraphy in detecting vesicoureteric reflux

“…However, a disparity exists among these guidelines in terms of the imaging modality to be performed and the exact protocol to be followed [13,14]. MCUG has a number of disadvantages including invasive nature, radiation exposure, the risk of secondary infection and significant discomfort for the patient [22,23]. Previous studies have suggested that DMSA scanning can obviate the need for MCUG examination in infants and younger children presenting with first febrile urinary tract inection [16].…”

Evaluation of occupational and patient radiation doses in orthopedic surgery

“…A calibrated X ray machine Toshiba, model DRX-1603B was used under reproducible reference conditions to deliver a known absorbed dose to the TLDs. For the TLD and chamber irradiation, a polymethylmethacrylate (PMMA) calibration test bed was constructed having dimensions 30x30x10 cm 3 , which simulates the patient's lateral and backscatter conditions (Martin et al, 1998, Sulieman et al, 2007. The first PMMA slab was used to accommodate the TLD chips in an array of slots 10x10.…”

“…The effective dose to the organs and tissues has been calculated using the methodology and tissue weighting factors reported at NCRP 122, 1995 andICRP 103, 2007, respectively. A computer program was developed, allowing calculation of the dose to 14 organs and tissues (Sulieman et al, 2007).…”

Avaliação das doses de radiação em uretrocistografia miccional de crianças

“…Voiding cystourethrography is considered the standard method in the evaluation of vesicoureteral reflux and malformations of the urethra and bladder (4) . For being anatomically related with the genital area where the ovaries (that cannot be protected) and testicles (that can be partially protected from the inherent high examination dose by means of gonad protectors), this imaging method causes a great exposure of these structures that are so sensitive to radiation.…”

“…of the urinary tract and, according to reports in the literature, represents 30% to 50% of fluoroscopy studies performed in children (3,4) . The main indications for this imaging method are: evaluation of repeated urinary infections, vesicoureteral reflux and congenital abnormalities of the bladder and of the urethra.…”