Room: AAPM ePoster Library
Purpose: directly measure radiation dose to the skin of patients undergoing fluoroscopically-guided neuroradiology interventional (FGNI) surgeries using optically stimulate luminescence dosimeters (OSLDs). In addition, the number of cases with measured peak skin doses (PSDs) exceeding the National Council on Radiation Protection & Measurements’ (NCRP) recommended radiation dose threshold of 2 Gray (Gy) for the deterministic skin effect of erythema will be identified.
Methods: OSLD-holding cap was developed for placement on the skull of patients undergoing FGNI surgeries performed with a Philips Allura Clarity bi-plane fluoroscopy unit. Under IRB approval, 31 patients consented to have the OSLD-holding cap placed on them during their FGNI surgery. PSDs were measured for clinically-relevant skin regions, such as the base of the skull. A linear regression between the calculated air kerma (AK) and the measured PSD was created.
Results: OSLD-holding cap did not interfere with physician ability to view relevant patient anatomy during FGNI surgery. Measured PSD exceeded the 2 Gy erythema threshold in 1 of 31 (3%) of patients by 200 mGy. 20 and 11 patients underwent therapeutic and diagnostic FGNI surgeries, respectively. The therapeutic procedures had an average higher dose by 718.23 mGy. The diagnostic procedures had on average lower PSDs by 141.52 mGy. The measured PSD and calculated AK were strongly correlated (R² ? 0.95).
Conclusion: methodology for PSD measurement of an FGNI surgery patient was developed and implemented in this clinical study. With a sample of 31 patients, a concrete recommendation for physician use of radiation cannot be made at this time. Angular dependence corrections on the OSLD measurement is recommended, this may reduce the associated dose uncertainty by 20%.
In Vivo Dosimetry, Image-guided Surgery, Fluoroscopy