Intestinal biospy in children with coeliac disease; a Swedish national study of radiation dose and risk

In paediatric patients, fluoroscopy is used to monitor intestinal biopsies obtained for the diagnosis of coeliac disease. The radiation dose to the child is dependent on the equipment, the sedation of the patient and the experience of the operator. This study presents patient measurements from a national study in Sweden. The cancer excess lifetime mortality risk (CELMR) and the loss of life expectancy (LLE) are calculated for this patient group. TLD measurements were performed by dosemeters at 40 Swedish paediatric departments performing these biopsies. Information was received on sedation techniques, equipment used and fluoroscopy duration. An exponential curve fit was applied to the entrance and exit dose values and this dose distribution was integrated to get the integral dose. From this the mean absorbed dose in the irradiated volume was calculated. The mean and the median of the mean absorbed dose in the irradiated volume to the children was found to be 1.3 mGy (range 0.05-17.5 mGy) and 0.56 mGy respectively. The mean value of the entrance surface dose was 3.0 mGy (range 0.10-27.1 mGy) and the median was 1.4 mGy. The annual collective dose was calculated to 3.3 man Gy, based on 2500 biopsies per year. Variation in doses was found to depend on, e.g. the age of the equipment, focus to patient distance, sedation and operator experience. With this knowledge of doses received by the children in the diagnosis of coeliac disease, CELMR was found to be 0.5 per 25000 biopsies and LLE was 18 years. Recommendations are given on the proper choice of equipment for the reduction of fluoroscopy doses in pediatric radiology. (Author)