Evaluation of the dose to pediatric patients undergoing micturating cystourethrography examination and optimization of the examination.
OBJECTIVE
The aim of our work was to estimate the dose to paediatric patients undergoing micturating cystourethrography (MCU), and to optimize those examination procedures that were found to be particularly significant from the point of view of the radiation dose. At the same time it was also decided to evaluate the absorbed dose to the parents, who frequently assist the child during MCU.


METHODS
The study was carried out on 220 children undergoing micturatig cystourethrography, by measuring in vivo the dose equivalent entering and exiting from the patient with thermoluminescent dosimetry and the KAP (Kerma Area Product). From the latter, the imparted energy and the average absorbed dose to the patients were subsequently calculated.


RESULTS
The average absorbed dose was 0.69+/-0.54 mGy, with a variation interval of 0.126-3.110 mGy. A remarkable dispersion of the absorbed dose values was observed, also for subjects of similar size. This indicates that radiation protection of paediatric patients still allows for wide margins of optimization. In fact it was possible to verify that the dose depends not only on the size of the child, but also on his/her degree of cooperation, and on the technical ability of the operator. The latter aspect was estimated by comparing the doses delivered by two different physicians; differences by a factor of 5 were observed. The application of additional filtration of 2 mm of Al (total 5 mm Al) concurred to a dose reduction without significant variations in image quality. The effective dose received by the parents present during the examination was 4+/-7 microSv.


CONCLUSIONS
A specific feature of paediatric MCU is not only the amount of radiation dose, often not negligible, but also the remarkable variation of the dose values, even within the same age group. The specialist has an important role in the justification of the examination: the adoption of a specific protocol has allowed reduction of the number of children undergoing MCU. Optimization of the examination requires quality control on the equipment, as well as the adoption of good radiographic techniques and the provision of suitable environments for children. The present study has helped to focus the attention of practitioners on radiation protection and, consequently, to reduce the dose delivered to the children. The effective dose received by the parents showed that their presence can be justified provided that they are adequately protected.
Mantovani
Andrea
A
Servizio Fisica Sanitaria, Aziernda Ospedaliera della Valtellina e Valchiavenna, Sondrio.
Giroletti
Elio
E
D000293:Adolescent; D000465:Algorithms; D002648:Child; D002675:Child, Preschool; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011829:Radiation Dosage; D011859:Radiography; D012189:Retrospective Studies; D013819:Thermoluminescent Dosimetry; D014521:Urethra / Q000000981:diagnostic imaging*; D001743:Urinary Bladder / Q000000981:diagnostic imaging*; D014554:Urination