Patient dose map indications on interventional X-ray systems and validation with Gafchromic XR-RV3 film.

ABSTRACT

To help avoiding secondary effects of interventional procedures like skin damage, a dose map method has been developed to provide an indication of the local dose on a surface representative of individual patient shapes. To minimise user interactions, patient envelope shapes are automatically determined depending on simple patient data information. Local doses are calculated in 1-cm² areas depending on the estimated air kerma, table and gantry positions and system settings, taking into account the table and mattress attenuations and estimated backscatter from the patient. These local doses are cumulated for each location of the patient envelope during the clinical procedure. To assess the accuracy of the method, Gafchromic XR-RV3 films have been used in several operating configurations. Good visual agreements on cumulated dose localisation were obtained within the 1-cm² precision of the map and the dose values agreed within 24.9 % accuracy. The resulting dose map method has been integrated into GE Healthcare X-Ray angiographic systems and should help in the management of the dose by the users during the procedure.