Evaluation of organ and effective doses for CAG based on in-phantom dosimetry

Transcription

1 Evaluation of organ and effective doses for CAG based on in-phantom dosimetry Poster No.: C-0619 Congress: ECR 2013 Type: Scientific Exhibit Authors: Y. Matsunaga, A. Kawaguchi, S. Suzuki, Y. Takikawa, M Yamada ; Nagoya/JP, Toyota/JP, Toyoake-city, Aichi/JP Keywords: Radioprotection / Radiation dose, Interventional vascular, Cardiac, Catheter arteriography, Digital radiography, Experimental, Dosimetry, Radiation safety, Radiation effects, Dosimetric comparison DOI: /ecr2013/C-0619 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 14

2 Purpose In recent years, radiographic systems equipped with a flat panel detector (FPD) have entered mainstream use in interventional radiology. Although there have been many reports on radiation dose assessment for patients undergoing percutaneous coronary intervention (PCI) or catheter cauterization with such systems, there have been few papers on dose assessments for patients undergoing diagnostic catheterization procedures, such as coronary angiography (CAG). In the present study, radiation doses were determined at various positions during diagnostic cardiac catheterization with an FPD-based system. Effective doses were calculated using the weighting factor specified in the 2007 and 1990 Recommendations of the International Commission on Radiological Protection in order to estimate patient exposure to radiation during use of an FPD-based system. Methods and Materials Equipment Coronary angio system #Shimadzu Bransist Safire HB9 (direct-conversion FPD) Gridratio 11:1 pulse fluoro (15 pulses/s), digital angiography (15 frames/s) Measuring equipment #TLD chips: Kyokko MSO-S (Mg2SiO4) #TLD reader: Kyokko Model 3000 #Annealing oven: Kyokko Model AO-SL #Human body phantom: alderson RANDO phantom RAN-110 Page 2 of 14

3 Fig. 1: Coronary Angio System and Human Body Phantom. TLD Chips and Human Body Phantom References: Imaging, Nagoya kyoritsu hospital - Nagoya/JP A human body phantom was used to estimate patient exposure doses during CAG (Fig. 1). Thermoluminescence dosimeters (TLD) were placed at various positions on and in the phantom (Table 1). Doses were determined using exposure conditions for a series of examinations. Effective doses were then calculated using the weighting factor specified in the 2007 and 1990 Recommendations of the International Commission on Radiological Protection. Page 3 of 14

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5 Table 1: Tissue/Organ and TLD chips References: Imaging, Nagoya kyoritsu hospital - Nagoya/JP Absorbed and effective dose calculations The method for calculating absorbed dose, DT,R, was defined as follows: DT,R#M K F, where DT,R is the absorbed dose of a specified organ or tissue (T) due to the radiation (R); M is the TLD measurement value; K is a calibration factor that depends on tube voltage and tube filtration; and F is a factor that depends on the mass energy coefficient ratio of each organ to air. The method for calculating effective dose, E, which was introduced in the ICRP publication 60, is defined by a weighted sum of tissue equivalent dose as follows: E##wT HT##wT #WR DT,R, where E is the effective dose; wt is a tissue weighting factor (ICRP publications 60 and 103); HT is the equivalent dose; and WR is the radiation weighting factor. Conditions for fluoro and exposure. (Table 2) Filtration (fluoro#1.0mmal#0.6mmcu exposure:1mmal) Page 5 of 14

6 Table 2: Fluoro and Exposure Conditions References: Imaging, Nagoya kyoritsu hospital - Nagoya/JP Images for this section: Fig. 1: Coronary Angio System and Human Body Phantom. TLD Chips and Human Body Phantom Page 6 of 14

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8 Table 1: Tissue/Organ and TLD chips Table 2: Fluoro and Exposure Conditions Page 8 of 14

9 Results The maximum dose point at the back of the phantom in our hospital CAG was an average absorbed dose of mgy, and in both lungs was mgy. The breast recieved 1.78 mgy, the esophagus recieved 1.67 mgy, and the gonads recieved 0.02 mgy (Fig. 2, Fig. 3). The effective dose in our hospital was 1.66 msv according to the 1990 recommendation, and 1.76 msv according to the 2007 recommendation (Fig. 4). Fig. 2: Organ dose (mgy) References: Imaging, Nagoya kyoritsu hospital - Nagoya/JP Page 9 of 14

10 Fig. 3: Entrance skin dose and Lung dose (mgy) References: Imaging, Nagoya kyoritsu hospital - Nagoya/JP Fig. 4: Effective dose (msv) References: Imaging, Nagoya kyoritsu hospital - Nagoya/JP Images for this section: Page 10 of 14

11 Fig. 2: Organ dose (mgy) Fig. 3: Entrance skin dose and Lung dose (mgy) Page 11 of 14

12 Fig. 4: Effective dose (msv) Page 12 of 14

13 Conclusion Patient dose during cardiac catheterization with a radiographic system equipped with a flat panel detector (FPD) was evaluated. Effective dose calculated using the weighting factor specified in 2007 was 1.76 msv. The maximum dose in the back of the entrance skin was mgy. The dose within and outside of the radiation field was calculated. The effective dose was found to be comparable with that of other radiographic examinations. References ICRP Publication 85. Avoidance of Radiation Injuries from Medical Interventional Procedures. Annals of the ICRP, Volume 30, No. 2, 25-30, ICRP Publication Recommendations of the International Commission on Radiological Protection. Volume 21, No.1-3, 4-24, ICRP Publication 103. The 2007 Recommendations of the International Commission on Radiological Protection. Annals of the ICRP Volume 37, No. 2-4, 62-71, Personal Information ############################################## Y. Matsunaga, A. Kawaguchi, S. Suzuki, 1 1 Y. Takikawa, M. Yamada ; 1 Nagoya Kyoritsu Hospital /JP, 2 Toyota Memorial Hospital /JP, 3 Fujita Health University /JP Correspondence address:yuta MATSUNAGA Department of Imaging,Nagoyakyoritsu hospital Page 13 of 14

14 Address# 1-172,Hokke,Nakagawa-ku,Nagoya,Aichi,Japan Tel# ############################################## Page 14 of 14