IADR Abstract Archives
Effective Dose of Cone Beam Computed Tomography: a Systematic Review
Objectives: To perform a systematic literature review concerning dosimetry of dentomaxillofacial CBCT imaging with emphasis on exposure protocols and factors affecting dose levels.
Methods: Studies published from 2007 to 2020, identified to MEDLINE®, Cochrane Library, Scopus and Trip Medical Database, using MeSH and free-text terms. The systematic review performed in compliance with PRISMA. Included original studies, used anthropomorphic dosimetry phantoms and dosimeters, utilized only tissue weights from the 2007 ICRP recommendations for calculating effective dose, including pertinent information regarding the scanner used, FOV size, exposure technique, phantom type and dosimeter used, published in English language. Studies without detailed description of exposure protocols and measurement methods were excluded. A data extraction sheet created to record effective doses, exposure protocols and measurement methods. Study screening and data extraction carried out independently by two observers. Statistical analysis performed with STATISTICA 12.5 software.
Results: From the 1834 articles initially retrieved, 1735 discarded (as they didn’t meet the inclusion criteria) and only 24 used since they met the inclusion criteria. Meta-analysis was not possible to be performed. Reported adult effective doses ranged from 4 to 461 μSv for small FOVs . Child effective doses ranged from 5-582 μSv for small FOVs, 7-769 for medium FOVs and 8-488 for large FOVs. In most cases an anthropomorphic phantom representing the skull of an adult male was used. Only in 4 cases pediatric phantoms corresponding to patients aged 10 years were used.
Conclusions: The most significant statistical correlation was found between the effective dose and the FOV and particularly the height of the FOV. So far, a generally accepted measurement protocol has not been adopted. A protocol with a minimum consensus on measurement methods is recommended. The most reliable dosimetry method is still based in anthropomorphic phantoms. The review discloses the need for a future study on effective doses related to various voxel sizes.
Methods: Studies published from 2007 to 2020, identified to MEDLINE®, Cochrane Library, Scopus and Trip Medical Database, using MeSH and free-text terms. The systematic review performed in compliance with PRISMA. Included original studies, used anthropomorphic dosimetry phantoms and dosimeters, utilized only tissue weights from the 2007 ICRP recommendations for calculating effective dose, including pertinent information regarding the scanner used, FOV size, exposure technique, phantom type and dosimeter used, published in English language. Studies without detailed description of exposure protocols and measurement methods were excluded. A data extraction sheet created to record effective doses, exposure protocols and measurement methods. Study screening and data extraction carried out independently by two observers. Statistical analysis performed with STATISTICA 12.5 software.
Results: From the 1834 articles initially retrieved, 1735 discarded (as they didn’t meet the inclusion criteria) and only 24 used since they met the inclusion criteria. Meta-analysis was not possible to be performed. Reported adult effective doses ranged from 4 to 461 μSv for small FOVs . Child effective doses ranged from 5-582 μSv for small FOVs, 7-769 for medium FOVs and 8-488 for large FOVs. In most cases an anthropomorphic phantom representing the skull of an adult male was used. Only in 4 cases pediatric phantoms corresponding to patients aged 10 years were used.
Conclusions: The most significant statistical correlation was found between the effective dose and the FOV and particularly the height of the FOV. So far, a generally accepted measurement protocol has not been adopted. A protocol with a minimum consensus on measurement methods is recommended. The most reliable dosimetry method is still based in anthropomorphic phantoms. The review discloses the need for a future study on effective doses related to various voxel sizes.