Cone-Beam Computed Tomography Examinations of the Head and Neck Region in Finland: Indications and Patient Radiation Dose
Turnbull-Smith, Sonja Benita
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Pään ja kaulan alueen kartiokeilatietokonetomografiatutkimukset Suomessa: indikaatiot ja potilasannokset
Diagnostic reference levels (DRLs) are pre-determined dose levels employed for patient dose management in diagnostic radiology. Cone-beam computed tomography (CBCT) has gained significant popularity in the imaging of the head and neck region eliciting the need for DRLs for CBCT examinations. The main objective of the study was to collect dose data for the establishment of indication-based national DRLs for CBCT examinations of the head and neck region in Finland as well as to form proposals for the prospective DRLs. In addition, examination frequencies, the use of optimised imaging parameters and the effect of manufacturer and model of the CBCT device on dose were studied. The study was conducted as a nation-wide dose survey among the Finnish facilities conducting CBCT examinations of the head and neck region. The response rate was 56% in terms of registered devices and 57% in terms of listed places of use. DRL proposals were made for seven indications. The values for the proposals were derived from the 75th percentile values of the indication-specific dose distributions. Very wide dose ranges were observed within all seven indications. The most common indication was pre-surgical imaging of implant treatments. A significant portion of the respondents had used default factory settings instead of optimising the imaging parameters. No particular manufacturer or device model stood out as producing exceptionally high or low doses regardless of the user. The Finnish DRLs for CBCT examinations will be issued based on the results of this study.