Room: Exhibit Hall | Forum 8
Purpose: This study investigates the radiation dose reduction properties of a lead cap on fluoroscopy operator brain dose using scattered radiation in a simulated clinical setting.
Methods: An anthropomorphic head phantom with dose bores drilled through the brain for the placement of a 0.6cc ion chamber calibrated to diagnostic energy ranges was positioned at a typical operator location next to a ceiling mounted C-arm unit. Tissue equivalent scattering material was placed in the beam. Measurements of scattered radiation at 3 locations in the head (left, right and center) at 2 different levels were made with and without a 0.5mm lead equivalent cap. Three primary angles (33 LAO, 0 and 33 RAO) were used to investigate angular dependence. The measured radiation dose in the brain and the system report KAP for each of the 18 setups was recorded with and without the lead cap. Percent dose reductions at each position and each level were calculated, as well as the overall dose per unit KAP with and without the lead cap.
Results: Dose reduction with the lead cap was dependent upon position, level and primary angle. The percent dose reduction was generally higher on the left side (closest to beam) than the right side. In some instances, increased dose in the brain was measured with the lead cap in place (due to internal scattering). Maximum dose reduction was 35%, and the maximum dose increase was 24%. Average dose reduction at two different levels in the brain across 3 lateral positions with the lead cap in place was 13%. The measured dose per KAP was 9.54 uGy/1000 uGymÂ² without the lead cap and 8.31 uGy/1000 uGymÂ² with the lead cap.
Conclusion: The whole brain radiation dose reduction properties of lead caps appears to be of limited value in a simulated clinical environment.
Not Applicable / None Entered.