Methodological quality of dental cone-beam CT diagnostic reference levels: a systematic review

Abstract Objective To evaluate the methodological quality of dental cone-beam CT (CBCT) diagnostic reference levels (DRLs) studies and reports, identify factors that limit DRL comparison, assess the level and methods of dose optimization, and clarify obstacles, both in dose optimization and DRL establishment. Methods A systematic search was applied across 5 databases and gray literature with International Atomic Energy Agency (IAEA) member countries contacted, to identify dental CBCT DRL studies and national reports. Studies/reports containing DRL establishment procedures, insufficient methodological detail, and adopted DRLs were excluded. Methodological quality was assessed using a modified Effective Public Health Practice Project tool, aligned with a checklist developed in accordance with International Commission on Radiological Protection (ICRP) 135. Results Of 320 reports screened, 19 were included. Diagnostic reference levels were clinical indication or field of view (FOV) based, using dose/kerma-area-product (DAP/KAP) metrics. Overall, 63% of studies had moderate methodological quality; DRL comparability was limited due to gaps or inconsistencies in reporting of exposure parameters, FOV, and heterogeneous indication grouping. Substantial dose variability was observed within the same clinical indications (2- to 10-fold) and FOV categories (3- to 10-fold), reflecting routine use of large FOVs irrespective of indication, reliance on manufacturer default protocols, limited understanding/education/training of exposure settings or optimization strategies, non-standardized system FOV settings, and unauthorized CBCT operators. Conclusions The majority of CBCT DRL studies are not of high quality. Improving DRL reporting quality requires interdisciplinary collaboration; digitized-dose recording with robust retrospective management of protocols, dose, indications; national dose registries for periodic dose audit; improved clinician education/engagement, strengthened regulatory oversight, and potentially international standardized frameworks.