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Tamura M, Kawamoto T, Ishifuro M, Tamura T, Masumoto Y, Kenjo M, Kiguchi M, Awai K, Nagata Y. Radio Frequency Identification Gate System to Identify Misused Personal Dosimeters. J Med Syst 2023; 47:107. [PMID: 37851155 DOI: 10.1007/s10916-023-02002-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 10/03/2023] [Indexed: 10/19/2023]
Abstract
The use of two personal dosimeters, one worn over and one worn under a protective apron, provides the best estimate of effective dose. However, inappropriate positioning of dosimeters is a common occurrence, resulting in abnormally high or low radiation exposure records. Although such incorrect positioning can be identified by radiation exposure records, doing so is time-consuming and labor-intensive for administrators. Therefore, a system that can identify incorrect locations of dosimeters without burdening administrators must be developed. In this study, we developed a radio frequency identification (RFID) gate system that can differentiate between two RFID-tagged dosimeters placed over and under a metal apron and identify misused dosimeters. To simulate the position of the RFID-tagged dosimeters, we designed four dosimeter-wearing classes, including "proper use" and three types of "misuse" (i.e., "reversed," "both under," and "both over"). When the system predicts "misuse" based on the tag reading, the worker is alerted with lights and alarms. The system performance was evaluated using a confusion matrix, with an overall accuracy of 97.75%, demonstrating high classification performance. The safety of the system against life support devices was also investigated, demonstrating that they were not affected by the electric field at 0.3 m or more from the antenna of the system under any transmit powers tested. This RFID gate system is highly capable of identifying incorrectly positioned dosimeters, enabling real-time monitoring of dosimeters to manage their positioning.
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Affiliation(s)
- Megumi Tamura
- Department of Clinical Support, Hiroshima University Hospital, Hiroshima, Japan.
| | | | - Minoru Ishifuro
- Department of Radiological Technology, Faculty of Medical Technology, Niigata University of Health and Welfare, Niigata, Japan
- Department of Orthopaedic Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Takayuki Tamura
- Department of Clinical Radiology, Faculty of Health Sciences, Hiroshima International University, Higashi-Hiroshima, Japan
| | - Yoshifumi Masumoto
- Department of Clinical Support, Hiroshima University Hospital, Hiroshima, Japan
| | - Masahiro Kenjo
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
| | - Masao Kiguchi
- Department of Clinical Support, Hiroshima University Hospital, Hiroshima, Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Hiroshima University Hospital, Hiroshima, Japan
| | - Yasushi Nagata
- Hiroshima High-Precision Radiotherapy Cancer Center, Hiroshima, Japan
- Department of Radiation Oncology, Hiroshima University, Hiroshima, Japan
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Cui L, Tian Q, Feng Z, Ma Y. What happened when medical staff in Beijing, China wore over-apron dosemeters? RADIATION PROTECTION DOSIMETRY 2023:7185476. [PMID: 37247844 DOI: 10.1093/rpd/ncad161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 04/26/2023] [Accepted: 05/01/2023] [Indexed: 05/31/2023]
Abstract
The wearing method of personal dosemeters for medical staff changed from under to outside the operator's protective apron in April 2020. We measured the radiation dose Hp(10) for medical staff in Beijing from September 2020 to October 2021. The study population consisted of 3291 medical staff. All participants were divided into three groups. After excluding unusually low doses, the collected data higher than the detection limit involved 811 (7.8%) of 10 395 readings from 479 (14.6%) of 3291 staff. The mean equivalent dose was 1.4 mSv/3 months, with an SD of 2.3 mSv. The calculated average annual effective doses of radiation workers in the three groups after the interventional procedures from September 2020 to October 2021 ranged from 0.47 to 0.63 mSv/year, with median values of 0.32, 0.23 and 0.26 mSv/year, respectively.
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Affiliation(s)
- Limeng Cui
- Department of Radiation Protection, Beijing Center for Disease Prevention and Control, Beijing, China
| | - Qingxiang Tian
- Department of Radiation Protection, Beijing Center for Disease Prevention and Control, Beijing, China
| | - Zechen Feng
- Department of Radiation Protection, Beijing Center for Disease Prevention and Control, Beijing, China
| | - Yongzhong Ma
- Department of Radiation Protection, Beijing Center for Disease Prevention and Control, Beijing, China
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Tamura M, Kawamoto T, Kenjo M, Nakashima T, Kawano R, Tamura T, Ishifuro M, Kiguchi M, Awai K, Nagata Y. Evaluation of Inappropriate Positioning of Dosimeters in Medical Workers Based on Dose Equivalent Hp(10). HEALTH PHYSICS 2023; 124:10-16. [PMID: 36331308 DOI: 10.1097/hp.0000000000001619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
This report presents a new method to characterize the inappropriate positioning of dosimeters based on the dose equivalent Hp(10). The Hp(10) values of medical workers were measured monthly for 12 mo using two personal dosimeters. Using the ratio between the values of Hp(10) recorded from dosimeters worn over and under protective aprons [Hp(10) over and Hp(10) under , respectively], 670 pairs of dosimeter readings were categorized into a proper use group [Hp(10) over /Hp(10) under ≥ 5] and a misuse group [Hp(10) over /Hp(10) under < 5]. Following personal interviews, the readings in the misuse group were classified into the following six subgroups: "reversed," "sometimes reversed," "both under," "both over," "without apron," and "not specified." Ultimately, the scatter plot of "Hp(10) over - Hp(10) under " vs. Hp(10) over was identified as the most promising tool for clarifying the misuse patterns of dosimeters, as individual readings were mapped to the locations of the corresponding subgroups in the obtained graphs. Our results are expected to facilitate efficient and accurate usage of dosimeters by medical workers.
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Affiliation(s)
- Megumi Tamura
- Department of Clinical Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Takeshi Kawamoto
- Writing Center, Hiroshima University, 1-2-2 Kagamiyama, Higashi-Hiroshima 739-8512, Japan
| | - Masahiro Kenjo
- Hiroshima High-Precision Radiotherapy Cancer Center, 1-2-3 Futabanosato, Higashi-ku, Hiroshima 732-0057, Japan
| | - Takeo Nakashima
- Department of Clinical Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Reo Kawano
- Clinical Research Center in Hiroshima, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Takayuki Tamura
- Department of Clinical Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Minoru Ishifuro
- Faculty of Human Sciences, University of Human Arts and Sciences, 1288 Magome, Iwatsuki-ku, Saitama 339-8539, Japan; formerly at Department of Clinical Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Masao Kiguchi
- Department of Clinical Support, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Kazuo Awai
- Department of Diagnostic Radiology, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Yasushi Nagata
- Department of Radiation Oncology, Hiroshima University Hospital, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
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Yoder RC, Dauer LT, Balter S, Boice JD, Grogan HA, Mumma MT, Passmore CN, Rothenberg LN, Vetter RJ. Dosimetry for the study of medical radiation workers with a focus on the mean absorbed dose to the lung, brain and other organs. Int J Radiat Biol 2022; 98:619-630. [PMID: 30451566 PMCID: PMC9465996 DOI: 10.1080/09553002.2018.1549756] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND The reconstruction of lifetime radiation doses for medical workers presents special challenges not commonly encountered for the other worker cohorts comprising the Million Worker Study. METHODS The selection of approximately 175,000 medical radiation workers relies on using estimates of lifetime and annual personal monitoring results collected since 1977. Approaches have been created to adjust the monitoring results so that mean organ absorbed doses can be estimated. RESULTS Changes in medical technology and practices have altered the radiation exposure environments to which a worker may have been exposed during their career. Other temporal factors include shifts in regulatory requirements that influenced the conduct of radiation monitoring and the changes in the measured dose quantities. CONCLUSIONS The use of leaded aprons during exposure to lower energy X rays encountered in fluoroscopically based radiology adds complexity to account for the shielding of the organs located in the torso when dosimeters were worn over leaded aprons. Estimating doses to unshielded tissues such as the brain and lens of the eye become less challenging when dosimeters are worn at the collar above the apron. The absence of leaded aprons in the higher energy photon settings lead to a more straightforward process of relating dosimeter results to mean organ doses.
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Affiliation(s)
| | | | | | - John D. Boice
- National Council on Radiation Protection and Measurements, Bethesda, MD, USA;,Vanderbilt Epidemiology Center, Division of Epidemiology Department of Medicine, Vanderbilt-Ingram Cancer Center Vanderbilt University Medical Center, Nashville, TN, USA
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Borrego D, Yoder C, Balter S, Kitahara CM. Collar badge lens dose equivalent values among U.S. physicians performing fluoroscopically-guided interventional procedures. J Vasc Interv Radiol 2021; 33:219-224.e2. [PMID: 34748952 PMCID: PMC10388339 DOI: 10.1016/j.jvir.2021.10.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 10/22/2021] [Accepted: 10/29/2021] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To describe the range of occupational badge dose readings and annualized dose records among physicians performing fluoroscopically guided interventional (FGI) procedures using job title information provided by the same three major medical institutions in 2009, 2012, and 2015. METHODS The Radiation Safety Office of selected hospitals was contacted to request assistance with identifying physicians in a large commercial dosimetry database. All entries judged to be uninformative of occupational doses to FGI procedures staff were excluded. Monthly and annualized doses were described with univariate statistics and box-and-whisker plots. RESULTS The dosimetry dataset of interventional radiology staff contains 169 annual dose records from 77 different physicians and 698 annual dose records from 455 non-physicians. The median annualized lens dose equivalent values among physicians (11.9 mSv; IQR=6.9-20.0) was nearly threefold higher than non-physician medical staff assisting with FGI procedures (4.0 mSv; IQR=1.8-6.7) (P<0.001). During the study period, without eye protection, 25% (23 of 93) of the physician annualized lens dose equivalent values may have exceeded 20 mSv; for non-physician medical staff, this value was may have been exceeded 3.5% (6 of 173) of the time. However, these values do not account for eye protection. CONCLUSION The findings from this study highlight the importance of mitigating occupational dose to the eyes of medical staff, particularly physicians, performing or assisting with FGI procedures. Training on radiation protection principles, the use of personal protective equipment, and patient radiation dose management can all help ensure occupational radiation dose is adequately controlled.
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Affiliation(s)
- David Borrego
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
| | - Craig Yoder
- Independent consultant, Weddington, North Carolina
| | - Stephen Balter
- Departments of Radiology and Medicine, Columbia University Medical Center, New York, New York
| | - Cari M Kitahara
- Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
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Borrego D, Kitahara CM, Balter S, Yoder C. Occupational Doses to Medical Staff Performing or Assisting with Fluoroscopically Guided Interventional Procedures. Radiology 2020; 294:353-359. [PMID: 31769743 PMCID: PMC6996708 DOI: 10.1148/radiol.2019190018] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 09/30/2019] [Accepted: 10/02/2019] [Indexed: 11/11/2022]
Abstract
Background Staff who perform fluoroscopically guided interventional (FGI) procedures are among the most highly radiation-exposed groups in medicine. However, there are limited data on monthly or annual doses (or dose trends over time) for these workers. Purpose To summarize occupational badge doses (lens dose equivalent and effective dose equivalent values) for medical staff performing or assisting with FGI procedures in 3 recent years after accounting for uninformative values and one- versus two-badge monitoring protocol. Materials and Methods Badge dose entries of medical workers believed to have performed or assisted with FGI procedures were retrospectively collected from the largest dosimetry provider in the United States for 49 991, 81 561, and 125 669 medical staff corresponding to years 2009, 2012, and 2015, respectively. Entries judged to be uninformative of occupational doses to FGI procedures staff were excluded. Monthly and annual occupational doses were described using summary statistics. Results After exclusions, 22.2% (153 033 of 687 912) of the two- and 32.9% (450 173 of 1 366 736) of the one-badge entries were judged to be informative. There were 335 225 and 916 563 of the two- and one-badge entries excluded, respectively, with minimal readings in the above-apron badge. Among the two-badge entries, 123 595 were incomplete and 76 059 had readings indicating incorrect wear of the badges. From 2009 to 2015 there was no change in lens dose equivalent values among workers who wore one badge (P = .96) or those who wore two badges (P = .23). Annual lens dose equivalents for workers wearing one badge (median, 6.9 mSv; interquartile range, 3.8213.8 mSv; n = 6218) were similar to those of staff wearing two badges (median, 7.1 mSv; interquartile range, 4.6-11.2 mSv; n = 1449) (P = .18), suggesting a similar radiation environment. Conclusion These workers are among the highest exposed to elevated levels of ionizing radiation, although their occupational doses are within U.S. regulatory limits. This is a population that requires consistent and accurate dose monitoring; however, failure to return one or both badges, reversal of badges, and improper badge placement are a major hindrance to this goal. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Karellas in this issue.
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Affiliation(s)
- David Borrego
- From the Radiation Epidemiology Branch, Division of Cancer
Epidemiology and Genetics, National Cancer Institute, National Institutes of
Health, 9609 Medical Center Dr, Bethesda, MD 20892-9778 (D.B., C.M.K.);
Departments of Radiology and Medicine, Columbia University Medical Center, New
York, NY (S.B.); and Independent consultant, Weddington, NC (C.Y.)
| | - Cari M. Kitahara
- From the Radiation Epidemiology Branch, Division of Cancer
Epidemiology and Genetics, National Cancer Institute, National Institutes of
Health, 9609 Medical Center Dr, Bethesda, MD 20892-9778 (D.B., C.M.K.);
Departments of Radiology and Medicine, Columbia University Medical Center, New
York, NY (S.B.); and Independent consultant, Weddington, NC (C.Y.)
| | - Stephen Balter
- From the Radiation Epidemiology Branch, Division of Cancer
Epidemiology and Genetics, National Cancer Institute, National Institutes of
Health, 9609 Medical Center Dr, Bethesda, MD 20892-9778 (D.B., C.M.K.);
Departments of Radiology and Medicine, Columbia University Medical Center, New
York, NY (S.B.); and Independent consultant, Weddington, NC (C.Y.)
| | - Craig Yoder
- From the Radiation Epidemiology Branch, Division of Cancer
Epidemiology and Genetics, National Cancer Institute, National Institutes of
Health, 9609 Medical Center Dr, Bethesda, MD 20892-9778 (D.B., C.M.K.);
Departments of Radiology and Medicine, Columbia University Medical Center, New
York, NY (S.B.); and Independent consultant, Weddington, NC (C.Y.)
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Pradhan AS, Lee JI, Kim JL. On the scenario of passive dosimeters in personnel monitoring: Relevance to diagnostic radiology and fluoroscopy-based interventional cardiology. J Med Phys 2016; 41:81-4. [PMID: 27217618 PMCID: PMC4871007 DOI: 10.4103/0971-6203.181634] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- A. S. Pradhan
- Radiation Dosimetry Team, Korea Atomic Energy Research Institute, Yuseong, Daejeon, Republic of Korea
| | - J. I. Lee
- Radiation Dosimetry Team, Korea Atomic Energy Research Institute, Yuseong, Daejeon, Republic of Korea
| | - J. L. Kim
- Radiation Dosimetry Team, Korea Atomic Energy Research Institute, Yuseong, Daejeon, Republic of Korea
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