Comparison of Effective Dose From Intraoperative 3D Imaging Using Mobile and Fixed C-Arms Versus Computed Tomography When Evaluating the Lumbar Spine.

Abstract

Study designExperimental Study.ObjectivesIntraoperative three-dimensional (3D) imaging has been shown to increase patient safety by assuring proper implant placement and often makes postoperative CT imaging obsolete. Nonetheless, there is no data about effective radiation doses in comparison to CT imaging.MethodsEffective doses of 3D and CT scans were measured with an anthropomorphic phantom (CIRS Inc, ATOM® Dosimetry Phantoms, Norfolk, VA, USA). Clinical presets of the C-arms were used and measured separately (mobile: Cios Spin; fixed: ARTIS pheno; both Siemens Healthcare GmbH, Erlangen, Germany). For CT imaging, a protocol for high-contrast imaging was used (SOMATOM X.cite, Siemens Healthcare GmbH, Erlangen, Germany).ResultsDepending on presets, effective doses with the mobile C-arm ranged from .51 ± .02 mSv (dose-sparing preset) to 3.14 ± .01 mSv (high-quality preset, <i>P</i> < .001). With the fixed C-arm, the effective dose ranged from .52 ± .0 mSv (dose-sparing preset) to 1.6 ± .02 mSv (standard-quality preset, <i>P</i> < .001). With CT imaging, the effective dose was 2.0 mSv.ConclusionsWhen evaluating the lumbar spine, the effective dose from intraoperative 3D imaging using mobile and fixed C-arms is comparable to that from CT scans.Proper choice of intraoperative protocol is essential, as there can be up to a 6-fold variation in dose between protocols. Intraoperative 3D imaging with (mobile or fixed) C-arms has been proven to avoid revision surgery. In this study, effective doses were shown to be comparable to those of CT scans. To avoid unnecessary exposure, indications need to be clear, and the choice of acquiring settings must respect the ALARA principle ("as low as reasonably achievable").