An analysis of patient dose received during cone-beam computed tomography in relation to scan settings and imaging indications as seen in a dental institution in order to establish institutional diagnostic reference levels

Abstract

Objectives: To investigate the dose-area product (DAP) of cone-beam computed tomography (CBCT) examinations for different scan settings and imaging indications, and to establish institutional diagnostic reference levels (DRLs) for dose optimization. Methods: A retrospective analysis of the DAP values of 3568 CBCT examinations taken from two different devices at the Prince Philip Dental Hospital, Hong Kong between 2016 and 2021 was performed. Patient- (age, gender, and imaging indication) and imaging-related (CBCT device, field-of-view (FOV), and voxel size) were correlated with the DAPs. The indication-oriented third-quartile DAP values were compared with DRLs from the UK, Finland, and Switzerland. The obtained third-quartile DAPs lower than the national DRLs and those for which no national DRLs have been proposed were used to establish institutional DRLs. Results: In the investigated CBCTs, the DAP value for large FOV scans was significantly lower than medium/small FOVs. CBCTs with a small voxel size exhibited a significantly higher DAP than those with a medium/large voxel size. CBCTs for endodontic, periodontal, orthodontic, or orthognathic evaluation exhibited a significantly higher DAP than other indications. Twelve indication-oriented institutional DRLs were established and five of them were lower than the national DRLs: third molars (229 mGy×cm2), jaw cysts/tumors (410 mGy×cm2), maxillary sinus pathology (520 mGy×cm2), developing dentition (164 mGy×cm2), and periapical lesions (564 mGy×cm2). Conclusions: CBCT examinations for endodontic, periodontal, orthodontic, or orthognathic evaluation may deliver a higher radiation dose to the patient than other imaging tasks. A periodic review of the patient dose from CBCT imaging and establishment of institutional DRLs for specific clinical settings are needed for monitoring patient dose and to optimize indication-oriented scanning protocols.

A comprehensive review and update on the current state of computer-assisted rehabilitation in implant dentistry

“…22 Regarding CBCT it must be understood that image quality and high image resolution are always associated with higher radiation doses. 23 In guided surgery, the voxel size of 0.2mm 3 is an adequate resolution serving guided surgery with low noise and a moderate radiation burden. Limiting the FOV as much as possible, minimising retakes, and using bespoke exposure parameters are additional measures that serve the purpose of reducing the radiation exposure in guided implant rehabilitation.…”

Cone Beam Computed Tomography in Implant Dentistry- An update

“…To optimize this radiation exposure and to support dentists in doing so, dose-reference levels (DRNs) are gradually being introduced in dental radiology [17]. This is already common practice in medical radiology.…”

The Use of CBCT in Evaluating the Health and Pathology of the Maxillary Sinus

“…One quality assurance measure to optimize the radiation dose is to establish institutional or national dose reference levels (DRLs) for each indication of CBCT examinations. For instance, it was suggested that the DRL for a CBCT examination to evaluate maxillary sinus pathology could be in the range of 520–1150 mGy × cm 2 [ 24 ]. Another measure is to enhance user training to minimize the chance of a retake due to inadequate diagnostic value of the original scan.…”