IAEA survey of dental cone beam computed tomography practice and related patient exposure in nine Central and Eastern European countries

Objectives: Cone beam CT (CBCT) in dentistry and maxillofacial surgery is a widely used imaging method for the assessment of various maxillofacial and dental pathological conditions. The objective of this study was to summarize the results of a multinational retrospective-prospective study that focused on patient exposure in this modality. Methods: The study included 27 CBCT units and 325 adult and paediatric patients, in total. Data on patients, clinical indications, technical parameters of exposure, patient dose indicator, or, alternatively, dose to phantom were collected. The dose indicator used was air kerma-area product, P-KA. Results: In most scanners operators are offered with a variety of options regarding technical parameters, especially the field of view size. The median and the third quartile value of P-KA for adult patients in 14 different facilities were 820 mGy cm(2) and 1000 mGy cm(2) (interquartile range = 1058 mGy cm(2)), and 653 mGy cm(2) and 740 mGy cm(2) (interquartile range = 1179 mGy cm(2)) for children, as reported by four different institutions. Phantom dose data were reported from 15 institutions, and median P-KA ranged from 125 mGy cm(2) to 1951 mGy cm(2). Median P-KA values varied by more than a 10-fold between institutions, mainly due to differences in imaging protocol used, in particular field of view and tube current-exposure time product. Conclusions: The results emphasize the need for a cautious approach to using dental CBCT. Imaging only when the clinical indications are clear, accompanied with the appropriate radiographic techniques and the optimum imaging protocol, will help reduce radiation dose to patients.