IN-CLINIC CALIBRATION OF A KERMA-AREA PRODUCT METER AT DIFFERENT RADIATION QUALITIES FOR THE ASSESSMENT OF SKIN DOSES INCURRED DURING INTERVENTIONAL FLUOROSCOPIC PROCEDURES

Date/Time
Date(s) - 11/02/2012
10:30 am

David Borrego, BME-Medical Physics Masters Student

Chair:
Wesley Bolch

Abstract:
The growing use and increasing complexity of interventional fluoroscopic procedures has raised public health concerns regarding radiation exposure to both the patient’s skin and internal radiosensitive organs. Current dosimetry options available to clinicians and physicians fail to account for the dynamic nature of fluoroscopic procedures and anthropometric differences in-patient size. The University of Florida skin dose mapping and organ software overcome these challenges my making use of the Radiation Dose Structured Report and the UF hybrid adult patient-dependent series of computational phantoms; however, it still relies on measurements from the kerma-area product meter. The kerma-area product meter is only accurate to within ±35% to account for uncertainties in determining patient skin dose. In order to address the inherent uncertainty introduced into the skin dose software from the ionization chamber, calibration coefficients were introduced. The calibration coefficients show strong energy dependence and can be predicted with knowledge of the tube voltage and amount of filtration material in the beam. The skin dose mapping software is able to cull for those variables, calculate the calibration coefficient, and finally apply the corrections in its calculation of dose. Overall, this study was able to show that many of the clinical challenges encountered in dose reconstructions may be overcome to eventually provide physicians with accurate real-time skin dose information to better help them manage patient risk.