Assessment of Maximum Patient Skin Dose for Interventional Radiology Procedures: Method and Uncertainty Analysis
J Farah1*, A Trianni2, E Carinou3, J Dabin4, C Deangelis5, J Domienik6, Z Knezevic7, R Kopec8, F Malchair4, A Negri2, L Novak9, T Siiskonen10, F Vanhavere4, I Clairand1, (1) French Institute for Radiological Protection and Nuclear Safety, Fonteay-aux-roses, France, (2) Udine University Hospital S. Maria della Misericordia, Udine, Italy,(3) Greek Atomic Energy Commission, Athens,Greece,(4) Belgian Nuclear Research Centre, Mol,Belgium,(5) National Institute of Health, Rome,Italy,(6) Institute of Occupational Medicine, Lodz,Poland,(7) Rudjer Boskovic Institute, Zagreb,Croatia,(8) Polish Academy of Sciences, Krakow,Poland, (9) National Radiatopn Protection Institute, Prague, Czech Republic, (10) Radiation and Nuclear Safety Authority, Helsinki, FinlandSU-E-I-28 Sunday 3:00PM - 6:00PM Room: Exhibit Hall
Purpose: To develop a method for the assessment of patient's maximum skin dose in interventional radiology procedures.
Methods: In the framework of EURADOS WG12, a European measurement protocol was developed to determine fluoroscopy patient skin dose for interventional procedures. The method investigates the use of XR-RV3 gafchromic films, punctual TLDs and TLD sheets to intercept the X-ray beam and measure the maximum skin dose. Beside investigating the optimal detector positioning, the method also looks for the most appropriate reading equipments and process (post-exposure time analysis, projection vs. transmission scanning, etc.), calibration conditions (backscattering conditions, beam qualities etc.) and fitting procedure (inversely proportional to dose vs. traditionally-used polynomials) based on a careful uncertainty investigation, Finally, the different dosemters are compared to establish the most practical and efficient method for clinical practice.
Results: XR-RV3 films, being large area dosemeters, proved to reproduce with good accuracy the dose distribution over the patient skin. Nonetheless, significant dependence with beam energy and quality, reading and fitting process was observed, which introduces important uncertainties in maximum skin dose measurement. Meanwhile, TLDs enabled precise dose estimates with lower uncertainty values but point TLD detectors may implicate missing the maximum dose location on the patient skin. Thus, TLD sheets could represent the most adapted tool for the assessment of fluoroscopy-induced skin doses. However, nowadays, these are used only in few laboratories and remain inaccessible in clinical practice. The given recommendation on calibration, reading, fitting and data analysis will help Medical Physicists to conduct accurate dose assessments and optimize the radiation protection of the patient.
Conclusion: The developed protocol standardizes practices of patient skin dose estimates in interventional radiology. Based on these results, the assessment, at European level, of alerts for interventional procedures using real-time Kerma-Area Product and Cumulative Air Kerma as skin dose indicators will be carried out.
Funding Support, Disclosures, and Conflict of Interest: Research funded in the framework of EURADOS WG12. No disclosures, no conflict of interest.