Evaluating Eye Lens Dose for Interventional Radiologists Using Optically Stimulated Luminescence Dosimetry in a Clinical Environment

Abstract

The International Commission on Radiological Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP) have made recommendations to reduce the dose limit for the lens of the eye as a result of reviewing modern recent studies. In the medical community the work population that is impacted is the medical staff, whoich are routinely near patients while performing fluoroscopy procedures. which This results in staff exposures to primary and scattered X-ray beams. These exposures are likely to increase dose to their eye lens. In this project, a comparison between two dosimetric methodologies was performed to assess eye lens dose at MedStar Georgetown University Hospital (MedStar). The current MedStar methodology of wearing dosimeters in two positions: one on the collar, unshielded, and a second dosimetrdosimetery under the shielded apron. This methodology will was be compared to imbedding dosimeters within a cap head band. There was a difference between the filtration used in the two methodologies;, the MedStar dosimeters used filtration of approximately 460 mg/〖cm〗^2 while the head cap method used 300 mg/〖cm〗^2 which is the current recommended tissue depth for the lens of the eye. To properly compare the doses measured by the two systems, a ratio was performed on the dose measured by the MedStar dosimeter to the head cap measurement. The head cap dosimeters were calibrated using a Hopewell Model X-80 X-ray Beam irradiator using M-150 beam spectra. The aim of the study was to determine if placing dosimeters closer to the eyes can be a more accurate method of evaluating eye lens exposuredose. The study followed five surgeons who volunteered to wear the dosimetry systems for two wear periods, a total of (n=10) observations were made. This study failed to show a statistical difference in eye lens doses measured between the two dosimetric methods. The range of percent difference between the doses measured for each pair was -172% to 147%. The study was unable to make a determination as to the accuracy of the measurement, the failed comparison was likely due to wearing compliance. Future studies should focus on increasing the number of paired observations between the two methodologies. Studies should also focus on methods to enhance physician participation and ensure their willingness to wear assigned dosimetry. In addition, a follow-on study should focus on performing the comparison on a controlled scenario using phantoms.