Improved Dose Estimates for Fluoroscopically Guided Lumbar Epidural Injections.

Journal Article (Journal Article)

OBJECTIVE: The goal of the study was to determine the potential impact of system inaccuracies and table attenuation on fluoroscope-reported dose values. DESIGN: An Institutional Review Board-approved study was conducted to collect detailed acquisition and patient exposure data for fluoroscopy-guided lumbar epidural injections. BACKGROUND: System-reported dosimetry values, especially the air Kinetic Energy Released per unit MAss and dose-area product metrics, are routinely used for estimating the radiation burden to patients undergoing fluoroscopy-guided procedures. However, these metrics do not account for other factors, such as acquisition geometry, where the table may attenuate a substantial fraction of the x-ray intensity, and system dosimetry inaccuracies, which are only required to be accurate within ±35%. METHODS: Acquisition data from 46 patients undergoing fluoroscopy-guided lumbar epidural injections were collected to better estimate the true incident dose-area product. Gantry angles, x-ray technique factors, and field sizes were collected to characterize each procedure. Additionally, the fluoroscope dosimetry accuracy and table attenuation properties were evaluated as a function of kVp to generate the correction factors necessary for accurate dosimetry estimates. RESULTS: The system-reported values overestimated the total patient entrance dose-area product by an average of 34% (13-44%). Errors may be substantially higher for systems with less accurate fluoroscopes or more anterior-posterior projections. Correcting system-reported dosimetry values for systematic inaccuracies and variability can substantially improve fluoroscopic dose values. CONCLUSIONS: Including corrections for system output inaccuracies and acquisition factors such as table attenuation is necessary for any reliable assessment of radiation burden to patients associated with fluoroscopy-guided procedures.

Full Text

Duke Authors

Cited Authors

  • Mann, SD; Joshi, A; Shonyo, M; Wells, JR; Hoye, J; Agasthya, G; Reiman, R; Samei, E

Published Date

  • May 1, 2019

Published In

Volume / Issue

  • 20 / 5

Start / End Page

  • 971 - 978

PubMed ID

  • 30215781

Electronic International Standard Serial Number (EISSN)

  • 1526-4637

Digital Object Identifier (DOI)

  • 10.1093/pm/pny172


  • eng

Conference Location

  • England