Patient doses in lower limb angiography in a recently installed flat detector x-ray system

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1 Patient doses in lower limb angiography in a recently installed flat detector x-ray system Poster No.: C-0939 Congress: ECR 2011 Type: Authors: Keywords: DOI: Scientific Paper V. Tsapaki, D. Papavdis, P. Nikolopoulos, P. Maniatis, D. Fagrezos, E. Kolliakou, M. Giannila, A. Karagiorgi, C. Triantopoulou; Athens/GR Interventional vascular, Physics in radiology, Catheter arteriography, Angioplasty, Arteriosclerosis /ecr2011/C-0939 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 5

2 Purpose To present the first results on patient radiation dose using a recently installed large area flat detector X-ray machine and how these results can be used to optimise the procedures. Methods and Materials The study was conducted in Konstantopoulio General Hospital which is situated in Athens. The X-ray system that was used for the diagnostic lower limb angiography procedures was a Philips Integris Allura Xper FD20 fully digital monoplane machine with a flat detector (FD) (Philips Medical Systems, Best, The Netherlands). The technical characteristics of the X-ray system are found in Table 1. TABLE 1. Technical characteristics of the Philips Integris Allura Xper FD20 fully digital monoplane machine with flat detector (FD) (Philips Medical Systems, Best, The Netherlands) are presented in this table. X-ray machine K* FD size 30x40 Field of view (FOV) (cm) (diag ) 48, 42, 31, 27, 22, 19, 15 Pixel size (µm) 154 Icocenter to floor (cm) Focal spot to icocenter (cm) 81 Generator power (kw) 100 kv range (kv) Anode heat capacity (MUH) 2.4 Focal spot (mm) 0.4/0.7 Pulsed fluoroscopy 15 Fluoroscopy mode L, N, H** Cu filters 0.2/0.5/1.0 Cine rate (fr/sec) for vascular applications 0.5, 1, 2, 3, 4, 6 Kerma-Area Product (KAP) (Gy.cm 2 ) Yes Page 2 of 5

3 The patient survey included 42 patients. Lower limb angiography was selected since it is considered as one of the most common diagnostic IR procedures. One board certified senior interventional radiologist with sufficient knowledge of radiation protection measures, obtained in various radiation protection workshops, performed the above procedures. Patient informed consent was waived (in agreement with the Ethics Committee of the Hospitals) since no personal data of the patients were used and dosimetric measurements are standard practice for these procedures. Data collected during each procedure were: Kerma Area Product (KAP), cumulative dose (CD) in the interventional reference point, fluoroscopy time (T), number of acquired images (F), patient age, weight and height. The KAP meter was calibrated according to the National Protocol for Patient Dose Measurements in Diagnostic Radiology [14]. Results Mean values of patient age, weight and height were 62 years, 78 kg and 1.7 m respectively. Table 2 presents the range and median values of KAP, CD, T and F for the sample of patients in the study. TABLE 2. This table shows the range and median values of KAP, CD, T and F for the sample of patients in the study. KAP (Gycm 2 ) CD (mgy) T (min) F min max median As seen from Table 2, the analysis revealed a large range of results both in KAP and in CD which is a measure of the skin dose received by the patient. It is encouraging that the results were lower than European reference levels of 100 Gycm 2, 5 min and 300 images [15]. However, the 100-fold variation in KAP together with the fact that only one operator performed the procedures has shown the need for close monitoring of the procedures. It is possible that the installation of the new machine with the different operating characteristics and different modes has an influence on patient dose which will be closely looked the next few months. Page 3 of 5

4 None of the patients exceeded the CD threshold of 5000 mgy for patient follow up for skin radiation effects [16, 17]. Furthermore, from the 42 patients in the sample, only 3 were over 1000 mgy (patient 1: 1565 mgy, patient 2: 2405 mgy and patient 3: 4517 mgy). Conclusion It is encouraging that our results are lower than European reference levels just after installation of the new digital X-ray equipment. However, the extremely large ranges even under the control of a single operator reveal the need for optimisation. Continuation of data collection is intended for further detailed investigation. References 1. Lin PJ. Technical advances of interventional fluoroscopy and flat panel receptor. Health Phy 2008; 95(5): Bokou, Schreiner-Karoussou, Breisch R, Beissel J. Changing from image intensifier to flat detector technology for interventional cardiology procedures: a practical point of view. Radiat Prot Dosim 2008; 128 (1-3): Tsapaki V,Kottou S, Kollaros N, Dafnomili P, Koutelou M, Koulentianos E, Neofotistou V. Comparison of a conventional and a flat-panel digital system in Interventional Cardiology procedures. Br J Radiol 2004 Jul;77 (919): Hatakeyyama Y, Kakeda S, Korogi Y et al. Intracranial 2D and 3D DSA with flat panel detector of the direct conversion type: initial experience. Eur Radiol 2006; 16: Editorial. Radiation hazards for the patient in cardiological procedures. Heart 2001; 85: Smith IR, Rivers JT. Measures of Radiation Exposure in cardiac imaging and the impact of case complexity. Heart Lung Circ 2008 Jan 30 (Epub ahead of print). 7. Wiper A, Katira R, Roberts DH. Interventional cardiology: it;s a hairy business. Heart 2005; 91: FDA. FDA Public Health Advisory: Avoidance of serious X-ray-induced skin injuries to patients during fluoroscopically guided procedures; Padovani R, Bernardi G, Malisan MR, Vano E, Morocutti G, Fioretti PM. Patient dose related to the complexity of interventional cardiology procedures. Rad Prot Dosim 2001; 94(1-2): Cousins, C, Sharp C. Medical interventional procedures-reducing the radiation risks. Clin Radiol 2004; 59: Mahesh M. Fluoroscopy: Patient radiation exposure issues. Radiographics 2001; 21: Page 4 of 5

5 12. SENTINEL. Safety and Efficacy for New Techniques and Imaging using New Equipment to Support European Legislation. European Coordination Action ( ). article_3854_en.htm. Accessed 22/07/ Editorial. Delft conference proceedings 2008: safety and efficacy for new techniques and imaging using new equipment to support European legislation. Radiat Prot Dosim 2008; 29 (1-3): Institute of Physical Sciences in Medicine / NRPB / College of Radiographers. National Protocol for Patient Dose Measurements in Diagnostic Radiology. (Chilton: NRPB) (1992). 15. Vano E, Jarvinen H, Kosunen A et al. Patient dose in IR: A european survey. Radiat Prot Dosim 2008; 129 (1-3): Stecker MS, Balter S, Towbin RB, Miller DL, Vañó E, Bartal G, et al. Guidelines for Patient Radiation Dose Management. J Vasc Interv Radiol 2009; 20: Balter S, Hopewell JW, Miller DL, Wagner LK, Zelefsky MJ. Fluoroscopically guided interventional procedures: a review of radiation effects on patients' skin and hair. Radiology 2010; 254(2): Personal Information V. Tsapaki virginia@otenet.gr P. Maniatis pekatman@otenet.gr C. Triantopoulou ctriantopoulou@gmail.com Page 5 of 5