Pub Date : 2022-06-30DOI: 10.14407/jrpr.2021.00304
K. Ono, Takafumi Kumasawa, K. Shimatani, Masatoshi Kanou, I. Yamaguchi, N. Kunugita
Background: The present study investigated the radiation dose distribution of balloon kyphoplasty (BKP) among surgeons and medical staff, and this is the first research to observe such exposure in Japan.Materials and Methods: The study subjects were an orthopedic surgeon (n = 1) and surgical staff (n = 9) who intervened in BKP surgery performed at the National Hospital Organization Disaster Medical Center (Tokyo, Japan) between March 2019 and October 2019. Only disposable protective gloves (0.022 mmPb equivalent thickness or less) and trunk protectors were used, and no protective glasses or thyroid drapes were used.Results and Discussion: The surgery time per vertebral body was 36.2 minutes, and the fluoroscopic time was 6.8 minutes. The average exposure dose per vertebral body was 1.46 mSv for the finger (70 μm dose equivalent), 0.24 mSv for the lens of the eye (3 mm dose equivalent), 0.11 mSv for the neck (10 mm dose equivalent), and 0.03 mSv for the chest (10 mm dose equivalent) under the protective suit.The estimated cumulative radiation exposure dose of 23 cases of BKP was calculated to be 50.37 mSv for the fingers, 8.27 mSv for the lens, 3.91 mSv for the neck, and 1.15 mSv for the chest.Conclusion: It is important to know the exposure dose of orthopedic surgeons, implement measures for exposure reduction, and verify the safety of daily use of radiation during surgery and examination.
背景:本研究调查了球囊后凸成形术(BKP)在外科医生和医务人员中的辐射剂量分布，这是日本首次观察这种暴露的研究。材料与方法:研究对象为2019年3月至2019年10月在日本东京国立医院组织灾难医疗中心(National Hospital Organization Disaster Medical Center, Tokyo, Japan)进行BKP手术的一名骨科医生(n = 1)和手术人员(n = 9)。只使用一次性防护手套(0.022 mmPb当量厚度或以下)和躯干保护器，不使用防护眼镜或甲状腺罩。结果与讨论:每个椎体手术时间为36.2分钟，透视时间为6.8分钟。在防护服下，每个椎体的平均暴露剂量为手指1.46毫西弗(70 μm剂量当量)，眼晶体0.24毫西弗(3毫米剂量当量)，颈部0.11毫西弗(10毫米剂量当量)，胸部0.03毫西弗(10毫米剂量当量)。23例BKP患者的累积辐射暴露剂量估计为手指50.37毫西弗，眼镜8.27毫西弗，颈部3.91毫西弗，胸部1.15毫西弗。结论:了解骨科医生的照射剂量，实施减少照射的措施，在手术和检查过程中验证日常使用辐射的安全性是很重要的。
{"title":"Radiation Dose Distribution of a Surgeon and Medical Staff during Orthopedic Balloon Kyphoplasty in Japan","authors":"K. Ono, Takafumi Kumasawa, K. Shimatani, Masatoshi Kanou, I. Yamaguchi, N. Kunugita","doi":"10.14407/jrpr.2021.00304","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00304","url":null,"abstract":"Background: The present study investigated the radiation dose distribution of balloon kyphoplasty (BKP) among surgeons and medical staff, and this is the first research to observe such exposure in Japan.Materials and Methods: The study subjects were an orthopedic surgeon (n = 1) and surgical staff (n = 9) who intervened in BKP surgery performed at the National Hospital Organization Disaster Medical Center (Tokyo, Japan) between March 2019 and October 2019. Only disposable protective gloves (0.022 mmPb equivalent thickness or less) and trunk protectors were used, and no protective glasses or thyroid drapes were used.Results and Discussion: The surgery time per vertebral body was 36.2 minutes, and the fluoroscopic time was 6.8 minutes. The average exposure dose per vertebral body was 1.46 mSv for the finger (70 μm dose equivalent), 0.24 mSv for the lens of the eye (3 mm dose equivalent), 0.11 mSv for the neck (10 mm dose equivalent), and 0.03 mSv for the chest (10 mm dose equivalent) under the protective suit.The estimated cumulative radiation exposure dose of 23 cases of BKP was calculated to be 50.37 mSv for the fingers, 8.27 mSv for the lens, 3.91 mSv for the neck, and 1.15 mSv for the chest.Conclusion: It is important to know the exposure dose of orthopedic surgeons, implement measures for exposure reduction, and verify the safety of daily use of radiation during surgery and examination.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"37 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82229397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-31DOI: 10.14407/jrpr.2021.00199
K. Yoshimura
Background: Residential areas have some factors on the external exposure of residents, who usually spend a long time in these areas. Although various survey has been carried out by the government or the research institutions after the Fukushima Daiichi Nuclear Power Plant accident, the mechanism of radiocesium inventory in the terrestrial zone has not been cleared. To better evaluate the radiation environment, this study investigated the temporal changes in air dose rate and 137 Cs inventories (Bq/m 2 ) in residential areas and agricultural fields. Materials and Methods: Air dose rate and 137 Cs inventories were investigated in residential areas located in an evacuation zone at 5–8 km from the Fukushima Daiichi Nuclear Power Plant. From December 2014 to September 2018, the air dose rate distribution was investigated through a walking survey (backpack survey), which was conducted by operators carrying a γ -ray detector on their backs. Additionally, from December 2014 to January 2021, the 137 Cs inventories on paved and permeable grounds were also measured using a portable γ -ray detector. Results and Discussion: In the areas where decontamination was not performed, the air dose rate decreased faster in residential areas than in agricultural fields. Moreover, the 137 Cs inventory on paved surfaces decreased with time owing to the horizontal wash-off, while the 137 Cs inventory on permeable surfaces decreased dramatically owing to the decontamination activities. Conclusion: These findings suggest that the horizontal wash-off of 137 Cs on paved surfaces facilitated the air dose rate decrease in residential areas to a greater extent compared with agricultural fields, in which the air dose rate decreased because of the vertical migration of 137 Cs. Results of this study can explain the faster environmental restoration in a residential environment reported by previous studies.
{"title":"Radiation Monitoring in the Residential Environment: Time Dependencies of Air Dose Rate and 137Cs Inventory","authors":"K. Yoshimura","doi":"10.14407/jrpr.2021.00199","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00199","url":null,"abstract":"Background: Residential areas have some factors on the external exposure of residents, who usually spend a long time in these areas. Although various survey has been carried out by the government or the research institutions after the Fukushima Daiichi Nuclear Power Plant accident, the mechanism of radiocesium inventory in the terrestrial zone has not been cleared. To better evaluate the radiation environment, this study investigated the temporal changes in air dose rate and 137 Cs inventories (Bq/m 2 ) in residential areas and agricultural fields. Materials and Methods: Air dose rate and 137 Cs inventories were investigated in residential areas located in an evacuation zone at 5–8 km from the Fukushima Daiichi Nuclear Power Plant. From December 2014 to September 2018, the air dose rate distribution was investigated through a walking survey (backpack survey), which was conducted by operators carrying a γ -ray detector on their backs. Additionally, from December 2014 to January 2021, the 137 Cs inventories on paved and permeable grounds were also measured using a portable γ -ray detector. Results and Discussion: In the areas where decontamination was not performed, the air dose rate decreased faster in residential areas than in agricultural fields. Moreover, the 137 Cs inventory on paved surfaces decreased with time owing to the horizontal wash-off, while the 137 Cs inventory on permeable surfaces decreased dramatically owing to the decontamination activities. Conclusion: These findings suggest that the horizontal wash-off of 137 Cs on paved surfaces facilitated the air dose rate decrease in residential areas to a greater extent compared with agricultural fields, in which the air dose rate decreased because of the vertical migration of 137 Cs. Results of this study can explain the faster environmental restoration in a residential environment reported by previous studies.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"PP 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84855608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-30DOI: 10.14407/jrpr.2021.00108
M. Sasaki, Y. Fujimichi, Kazuo Yoshida, T. Iwasaki
Background: A comprehensive, traceable, and easy-to-understand radiation risk indicator is desired for radiological protection. The early-onset hypothesis could be used for this purpose.Materials and Methods: An indicator for early death (IED) was developed and calculated using the epidemiological dataset from the 14th Report of the Life Span Study (LSS) of Hiroshima and Nagasaki. By clarifying the calculation process, IED for all-cause mortality was estimated. In addition, the characteristics of IED for solid cancer mortality and cardiovascular mortality as well as those of men and women, and their dependence on age at exposure were investigated for detailed analysis.Results and Discussion: The IED for all-cause mortality was estimated to be approximately 4 years for an acute radiation exposure of 1 Gy regardless of the fitting dose range. The cumulative death rate for all solid cancers also indicated the early-death tendency (approximately 7–10 years at 1 Gy). Although, there is a slight difference in the characteristics of the risk obtained from the LSS study and this study, it is considered that the IED in a unit of years can also be used to show the overall picture of risk due to radiation exposure.Conclusion: We developed and calculated the indicator for early death, IED, for the cumulative mortality rate of all causes of death, all solid cancers, and circulatory diseases. The quantitative values of IED were estimated to be 4 years for all causes of death, 7–10 years for all solid cancers. IED has an advantage for intuitively understanding the meaning of radiation risk since it can be obtained by a simple and traceable method.
{"title":"Calculation of an Indicator for Early Death Using Atomic Bomb Survivors’ Data","authors":"M. Sasaki, Y. Fujimichi, Kazuo Yoshida, T. Iwasaki","doi":"10.14407/jrpr.2021.00108","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00108","url":null,"abstract":"Background: A comprehensive, traceable, and easy-to-understand radiation risk indicator is desired for radiological protection. The early-onset hypothesis could be used for this purpose.Materials and Methods: An indicator for early death (IED) was developed and calculated using the epidemiological dataset from the 14th Report of the Life Span Study (LSS) of Hiroshima and Nagasaki. By clarifying the calculation process, IED for all-cause mortality was estimated. In addition, the characteristics of IED for solid cancer mortality and cardiovascular mortality as well as those of men and women, and their dependence on age at exposure were investigated for detailed analysis.Results and Discussion: The IED for all-cause mortality was estimated to be approximately 4 years for an acute radiation exposure of 1 Gy regardless of the fitting dose range. The cumulative death rate for all solid cancers also indicated the early-death tendency (approximately 7–10 years at 1 Gy). Although, there is a slight difference in the characteristics of the risk obtained from the LSS study and this study, it is considered that the IED in a unit of years can also be used to show the overall picture of risk due to radiation exposure.Conclusion: We developed and calculated the indicator for early death, IED, for the cumulative mortality rate of all causes of death, all solid cancers, and circulatory diseases. The quantitative values of IED were estimated to be 4 years for all causes of death, 7–10 years for all solid cancers. IED has an advantage for intuitively understanding the meaning of radiation risk since it can be obtained by a simple and traceable method.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79625224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-30DOI: 10.14407/jrpr.2021.00220
M. Kowatari, K. Nagamoto, K. Nakagami, Y. Tanimura, T. Moritake, N. Kunugita
Background: For proper monitoring of the eye lens dose, an appropriate calibration factor of a dosimeter and information about the mean energies of X-rays are indispensable. The scattered X-ray energy spectra should be well characterized in medical practices where eye lenses of medical staffs might be high.Materials and Methods: Scattered X-ray energy spectra were experimentally derived for three different types of X-ray diagnostic and therapeutic equipment, i.e., the computed tomography (CT) scan, the angiography and the fluoroscopy. A commercially available CdZnTe (CZT) spectrometer with a lead collimator was employed for the measurement of scattered X-rays, which was performed in the usual manner.Results and Discussion: From the obtained energy spectra, the mean energies of the scattered X-rays lied between 40 and 60 keV. This also agreed with that obtained by the conventional half value layer method.Conclusion: The scattered X-rays to which medical workers may be exposed in the region around the eyes were characterized by means of spectrometry. The obtained mean energies of the scattered X-rays were found to match the flat region of the dosimeter response.
{"title":"Experimental Evaluation of Scattered X-Ray Spectra due to X-Ray Therapeutic and Diagnosis Equipment for Eye Lens Dosimetry of Medical Staff","authors":"M. Kowatari, K. Nagamoto, K. Nakagami, Y. Tanimura, T. Moritake, N. Kunugita","doi":"10.14407/jrpr.2021.00220","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00220","url":null,"abstract":"Background: For proper monitoring of the eye lens dose, an appropriate calibration factor of a dosimeter and information about the mean energies of X-rays are indispensable. The scattered X-ray energy spectra should be well characterized in medical practices where eye lenses of medical staffs might be high.Materials and Methods: Scattered X-ray energy spectra were experimentally derived for three different types of X-ray diagnostic and therapeutic equipment, i.e., the computed tomography (CT) scan, the angiography and the fluoroscopy. A commercially available CdZnTe (CZT) spectrometer with a lead collimator was employed for the measurement of scattered X-rays, which was performed in the usual manner.Results and Discussion: From the obtained energy spectra, the mean energies of the scattered X-rays lied between 40 and 60 keV. This also agreed with that obtained by the conventional half value layer method.Conclusion: The scattered X-rays to which medical workers may be exposed in the region around the eyes were characterized by means of spectrometry. The obtained mean energies of the scattered X-rays were found to match the flat region of the dosimeter response.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"86 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76249998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-30DOI: 10.14407/jrpr.2021.00227
Bo-Lun Lai, Szu-Li Chang, R. Sheu
Background: There are several proton therapy facilities in operation or planned in Taiwan, and these facilities are anticipated to not only treat cancer but also provide beam services to the industry or academia. The simplified approach based on the Monte Carlo-based data sets (source terms and attenuation lengths) with the point-source line-of-sight approximation is friendly in the design stage of the proton therapy facilities because it is intuitive and easy to use. The purpose of this study is to expand the Monte Carlo-based data sets to allow the simplified approach to cover the application of proton beams more widely.Materials and Methods: In this work, the MCNP6 Monte Carlo code was used in three simulations to achieve the purpose, including the neutron yield calculation, Monte Carlo-based data sets generation, and dose assessment in simple cases to demonstrate the effectiveness of the generated data sets.Results and Discussion: The consistent comparison of the simplified approach and Monte Carlo simulation results show the effectiveness and advantage of applying the data set to a quick shielding design and conservative dose assessment for proton therapy facilities.Conclusion: This study has expanded the existing Monte Carlo-based data set to allow the simplified approach method to be used for dose assessment or shielding design for beam services in proton therapy facilities. It should be noted that the default model of the MCNP6 is no longer the Bertini model but the CEM (cascade-exciton model), therefore, the results of the simplified approach will be more conservative when it was used to do the double confirmation of the final shielding design.
{"title":"Demonstration of the Effectiveness of Monte Carlo-Based Data Sets with the Simplified Approach for Shielding Design of a Laboratory with the Therapeutic Level Proton Beam","authors":"Bo-Lun Lai, Szu-Li Chang, R. Sheu","doi":"10.14407/jrpr.2021.00227","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00227","url":null,"abstract":"Background: There are several proton therapy facilities in operation or planned in Taiwan, and these facilities are anticipated to not only treat cancer but also provide beam services to the industry or academia. The simplified approach based on the Monte Carlo-based data sets (source terms and attenuation lengths) with the point-source line-of-sight approximation is friendly in the design stage of the proton therapy facilities because it is intuitive and easy to use. The purpose of this study is to expand the Monte Carlo-based data sets to allow the simplified approach to cover the application of proton beams more widely.Materials and Methods: In this work, the MCNP6 Monte Carlo code was used in three simulations to achieve the purpose, including the neutron yield calculation, Monte Carlo-based data sets generation, and dose assessment in simple cases to demonstrate the effectiveness of the generated data sets.Results and Discussion: The consistent comparison of the simplified approach and Monte Carlo simulation results show the effectiveness and advantage of applying the data set to a quick shielding design and conservative dose assessment for proton therapy facilities.Conclusion: This study has expanded the existing Monte Carlo-based data set to allow the simplified approach method to be used for dose assessment or shielding design for beam services in proton therapy facilities. It should be noted that the default model of the MCNP6 is no longer the Bertini model but the CEM (cascade-exciton model), therefore, the results of the simplified approach will be more conservative when it was used to do the double confirmation of the final shielding design.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"48 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80632721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-30DOI: 10.14407/jrpr.2021.00031
A. Srivastava, V. Chahar, Neeraj Chauhan, D. Krupp, U. Scherer
Background: Epidemiological observations such as mental retardation, physical deformities, etc., in children besides different types of cancer in the adult population of the Malwa region have been reported. The present study is designed to get insight into the role of naturally occurring radioactive material (NORM) in causing detrimental health effects observed in the general population of this region.Materials and Methods: Deep soil samples were collected from different locations in the Malwa region. Their activity concentrations were determined using low-level background gammaray spectrometry. High efficiency and high purity germanium detector capped in a lead-shielded chamber having a resolution of 1.8 keV at 1,173 keV and 2.0 keV at the 1,332 keV line of 60Co was used in the present work. Data were evaluated with Genie-2000 software.Results and Discussion: Mean activity concentrations of 238U, 232Th, and 40K in deep soil were found to be 101.3 Bq/kg, 65.8 Bq/kg, and 688.6 Bq/kg, respectively. The mean activity concentration of 238U was found to be three and half times higher than the global average prescribed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). It was further observed that the activity concentration of 232Th and 40K has a magnitude that is nearly one and half times higher than the global average prescribed by UNSCEAR. In addition, the radioisotope 137Cs which is likely to have its origin in radiation fallout was also observed. It is postulated that the NORM present in high quantity in deep soil somehow get mobilized into the water aquifers used by the general population and thereby causing harmful health problems.Conclusion: It can be stated that the present work has been able to demonstrate the use of low background gamma-ray spectrometry to understand the role of NORM in causing health-related effects in a general population of the Malwa region of Punjab, India.
{"title":"Study of Naturally Occurring Radioactive Material Present in Deep Soil of the Malwa Region of Punjab State of India Using Low Level Background Gamma-Ray Spectrometry","authors":"A. Srivastava, V. Chahar, Neeraj Chauhan, D. Krupp, U. Scherer","doi":"10.14407/jrpr.2021.00031","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00031","url":null,"abstract":"Background: Epidemiological observations such as mental retardation, physical deformities, etc., in children besides different types of cancer in the adult population of the Malwa region have been reported. The present study is designed to get insight into the role of naturally occurring radioactive material (NORM) in causing detrimental health effects observed in the general population of this region.Materials and Methods: Deep soil samples were collected from different locations in the Malwa region. Their activity concentrations were determined using low-level background gammaray spectrometry. High efficiency and high purity germanium detector capped in a lead-shielded chamber having a resolution of 1.8 keV at 1,173 keV and 2.0 keV at the 1,332 keV line of 60Co was used in the present work. Data were evaluated with Genie-2000 software.Results and Discussion: Mean activity concentrations of 238U, 232Th, and 40K in deep soil were found to be 101.3 Bq/kg, 65.8 Bq/kg, and 688.6 Bq/kg, respectively. The mean activity concentration of 238U was found to be three and half times higher than the global average prescribed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). It was further observed that the activity concentration of 232Th and 40K has a magnitude that is nearly one and half times higher than the global average prescribed by UNSCEAR. In addition, the radioisotope 137Cs which is likely to have its origin in radiation fallout was also observed. It is postulated that the NORM present in high quantity in deep soil somehow get mobilized into the water aquifers used by the general population and thereby causing harmful health problems.Conclusion: It can be stated that the present work has been able to demonstrate the use of low background gamma-ray spectrometry to understand the role of NORM in causing health-related effects in a general population of the Malwa region of Punjab, India.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88627083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-29DOI: 10.14407/jrpr.2021.00024
Chul Hang Kim, H. Choi, K. Kang, B. Jeong, Hojin Jeong, I. Ha, J. Song
1Department of Radiation Oncology, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Korea; 2Department of Biomedical Engineering, Pusan National University, Pusan, Korea; 3Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju, Korea; 4Department of Radiation Oncology, Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, Jinju, Korea; 5Department of Radiation Oncology, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
{"title":"Development and Evaluation of the Utility of a Respiratory Monitoring and Visual Feedback System for Radiotherapy Using Machine Vision Technology","authors":"Chul Hang Kim, H. Choi, K. Kang, B. Jeong, Hojin Jeong, I. Ha, J. Song","doi":"10.14407/jrpr.2021.00024","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00024","url":null,"abstract":"1Department of Radiation Oncology, Gyeongsang National University Changwon Hospital, Gyeongsang National University College of Medicine, Changwon, Korea; 2Department of Biomedical Engineering, Pusan National University, Pusan, Korea; 3Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju, Korea; 4Department of Radiation Oncology, Gyeongsang National University Hospital, Gyeongsang National University College of Medicine, Jinju, Korea; 5Department of Radiation Oncology, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"8 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84707125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-23DOI: 10.14407/jrpr.2022.00009
Hee Reyoung
Cadmium zinc telluride (CZT) is the most promising material to detect X-ray and gamma-ray due to its high detection efficiency, good energy resolution, and operability at room temperature without any cooling device. However, detector responses of the CZT depend on the interaction position because of the distributions of weighting potential in a planar electrode structure and material defects, and it causes the degradation of the performance. We developed a detection system based on a 3D position-sensitive detector to overcome this problem. A 5 × 5 × 12 mm3 CZT was used, and the virtual Frisch-grid (VFG) method was applied. 3D position information was calculated by signals from the anode, cathode, and side electrodes. The detector responses were corrected by the position information, and as a result, the energy resolution of 0.83% at 662 keV was achieved. We developed a prototype Compton camera by expanding the single VFG CZT detector to a 2 × 2 array. This array structure allows us to use small but high-yielding crystals, so a large-area detection system with a low cost can be achievable. Four 6 × 6 × 19 mm3 CZTs and a commercialized signal processing system were used. Positional information acquisition and response correction were performed the same way as the previous system. Various sources were used for spectroscopy, and the energy resolutions at 356, 511, 662, 1,275, and 1,332 keV were 3.17, 2.37, 2.03, 1.49, and 1.14%, respectively. In Compton imaging experiments, single and multiple sources at various positions were measured, and the weighted list-mode MLEM method was applied for image reconstruction. The results showed that our Compton camera could correctly reconstruct the source positions of either single or multiple sources. The intrinsic efficiency and spatial resolution evaluated by single 137Cs results were (1.43 ± 0.28) × 10-3 and 16.42 ± 5.35°, respectively. It was also identified that the different sources could be distinguished by applying energy windows. Name of graduate: Lee, Chanki Affiliation: Department of Nuclear Engineering/Ulsan National Institute of Science and Technology/Korea Graduation date: Feb. 2022 Degree: Doctor of Philosophy Name of academic advisor: Kim, Hee Reyoung Title of thesis: In Situ YAlO3(Ce) Gamma Spectrometry System for Underwater Survey by Remotely Operated Vehicle Abstract: Rapid surveys and assessments of environmental radioactivity and radiation doses are required for efficient and effective response to radiological emergencies. Emergency responses under underwater conditions to illegal ocean dumping, accidents, or sabotage of marine nuclear reactors are probably going to increase in the future. Therefore, in this study, we designed, developed, and tested a mechanical, chemical, and radiologically robust in situ YAlO3(Ce) gamma spectrometer survey system, that is remotely operated by an unmanned vehicle to be used for short-range and high-dose contaminations. In particular, the system is optimally
{"title":"List of Recent Graduates","authors":"Hee Reyoung","doi":"10.14407/jrpr.2022.00009","DOIUrl":"https://doi.org/10.14407/jrpr.2022.00009","url":null,"abstract":"Cadmium zinc telluride (CZT) is the most promising material to detect X-ray and gamma-ray due to its high detection efficiency, good energy resolution, and operability at room temperature without any cooling device. However, detector responses of the CZT depend on the interaction position because of the distributions of weighting potential in a planar electrode structure and material defects, and it causes the degradation of the performance. We developed a detection system based on a 3D position-sensitive detector to overcome this problem. A 5 × 5 × 12 mm3 CZT was used, and the virtual Frisch-grid (VFG) method was applied. 3D position information was calculated by signals from the anode, cathode, and side electrodes. The detector responses were corrected by the position information, and as a result, the energy resolution of 0.83% at 662 keV was achieved. We developed a prototype Compton camera by expanding the single VFG CZT detector to a 2 × 2 array. This array structure allows us to use small but high-yielding crystals, so a large-area detection system with a low cost can be achievable. Four 6 × 6 × 19 mm3 CZTs and a commercialized signal processing system were used. Positional information acquisition and response correction were performed the same way as the previous system. Various sources were used for spectroscopy, and the energy resolutions at 356, 511, 662, 1,275, and 1,332 keV were 3.17, 2.37, 2.03, 1.49, and 1.14%, respectively. In Compton imaging experiments, single and multiple sources at various positions were measured, and the weighted list-mode MLEM method was applied for image reconstruction. The results showed that our Compton camera could correctly reconstruct the source positions of either single or multiple sources. The intrinsic efficiency and spatial resolution evaluated by single 137Cs results were (1.43 ± 0.28) × 10-3 and 16.42 ± 5.35°, respectively. It was also identified that the different sources could be distinguished by applying energy windows. Name of graduate: Lee, Chanki Affiliation: Department of Nuclear Engineering/Ulsan National Institute of Science and Technology/Korea Graduation date: Feb. 2022 Degree: Doctor of Philosophy Name of academic advisor: Kim, Hee Reyoung Title of thesis: In Situ YAlO3(Ce) Gamma Spectrometry System for Underwater Survey by Remotely Operated Vehicle Abstract: Rapid surveys and assessments of environmental radioactivity and radiation doses are required for efficient and effective response to radiological emergencies. Emergency responses under underwater conditions to illegal ocean dumping, accidents, or sabotage of marine nuclear reactors are probably going to increase in the future. Therefore, in this study, we designed, developed, and tested a mechanical, chemical, and radiologically robust in situ YAlO3(Ce) gamma spectrometer survey system, that is remotely operated by an unmanned vehicle to be used for short-range and high-dose contaminations. In particular, the system is optimally","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"39 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86098494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-05DOI: 10.14407/jrpr.2021.00311
Y. Lim
Background: Radiation exposure can occur as a result of occupational activities utilizing sources of radiation. The average level of occupational exposure is generally similar to the global average, but some workers receive more than this. In this study, the occupational exposure data for workers in Korea to check the recent trend of radiation exposure. Materials and Methods: The data collection and analysis are carried out by two separate periods based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UN-SCEAR) survey. One is the year 2003 to 2014 for a recent survey, and the other is 2015 to 2019. All available data were collected by annual reports from radiation dose registry organizations. Results and Discussion: The annual dose over the record level to the total workers did not change much compared with the total increasing number of workers in this period. The dose to the nuclear fuel cycle field has a tendency to decrease. It resulted from the efforts of radiation dose reduction with high technology introduced to this area. Also, it is important result that the radiation dose to the workers in radiography is remarkably reduced. Conclusion: The number of radiation workers and average doses were analyzed for occupational categories in Korea. It still needs cooperative efforts between the dose registry organizations for the efficient dose management of Korean radiation workers.
{"title":"Recent Trend of Occupational Exposure to Ionizing Radiation in Korea, 2015–2019","authors":"Y. Lim","doi":"10.14407/jrpr.2021.00311","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00311","url":null,"abstract":"Background: Radiation exposure can occur as a result of occupational activities utilizing sources of radiation. The average level of occupational exposure is generally similar to the global average, but some workers receive more than this. In this study, the occupational exposure data for workers in Korea to check the recent trend of radiation exposure. Materials and Methods: The data collection and analysis are carried out by two separate periods based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UN-SCEAR) survey. One is the year 2003 to 2014 for a recent survey, and the other is 2015 to 2019. All available data were collected by annual reports from radiation dose registry organizations. Results and Discussion: The annual dose over the record level to the total workers did not change much compared with the total increasing number of workers in this period. The dose to the nuclear fuel cycle field has a tendency to decrease. It resulted from the efforts of radiation dose reduction with high technology introduced to this area. Also, it is important result that the radiation dose to the workers in radiography is remarkably reduced. Conclusion: The number of radiation workers and average doses were analyzed for occupational categories in Korea. It still needs cooperative efforts between the dose registry organizations for the efficient dose management of Korean radiation workers.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"13 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2022-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86399178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-30DOI: 10.14407/jrpr.2021.00171
Y. Sanada, Mutsushi Ishida, K. Yoshimura, S. Mikami
Background: The radionuclides released by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident 9 years ago are still being monitored by various research teams and the Japanese government. Comparison of different surveys’ results could help evaluate the exposure doses and the mechanism of radiocesium behavior in the urban environment in the area. In this study, we clarified the relationship between land use and temporal changes in the ambient dose rates (air dose rates) using big data.Materials and Methods: We set a series of 1 × 1 km2 meshes within the 80 km zone of the FDNPP to compare the different survey results. We then prepared an analysis dataset from all survey meshes to analyze the temporal change in the air dose rate. The selected meshes included data from all survey types (airborne, fixed point, backpack, and carborne) obtained through the all-time survey campaigns.Results and Discussion: The characteristics of each survey’s results were then evaluated using this dataset, as they depended on the measurement object. The dataset analysis revealed that, for example, the results of the carborne survey were smaller than those of the other surveys because the field of view of the carborne survey was limited to paved roads. The location factor of different land uses was also evaluated considering the characteristics of the four survey methods. Nine years after the FDNPP accident, the location factor ranged from 0.26 to 0.49, while the half-life of the air dose rate ranged from 1.2 to 1.6.Conclusion: We found that the decreasing trend in the air dose rate of the FDNPP accident was similar to the results obtained after the Chernobyl accident. These parameters will be useful for the prediction of the future exposure dose at the post-accident.
{"title":"Comparison of Dose Rates from Four Surveys around the Fukushima Daiichi Nuclear Power Plant for Location Factor Evaluation","authors":"Y. Sanada, Mutsushi Ishida, K. Yoshimura, S. Mikami","doi":"10.14407/jrpr.2021.00171","DOIUrl":"https://doi.org/10.14407/jrpr.2021.00171","url":null,"abstract":"Background: The radionuclides released by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident 9 years ago are still being monitored by various research teams and the Japanese government. Comparison of different surveys’ results could help evaluate the exposure doses and the mechanism of radiocesium behavior in the urban environment in the area. In this study, we clarified the relationship between land use and temporal changes in the ambient dose rates (air dose rates) using big data.Materials and Methods: We set a series of 1 × 1 km2 meshes within the 80 km zone of the FDNPP to compare the different survey results. We then prepared an analysis dataset from all survey meshes to analyze the temporal change in the air dose rate. The selected meshes included data from all survey types (airborne, fixed point, backpack, and carborne) obtained through the all-time survey campaigns.Results and Discussion: The characteristics of each survey’s results were then evaluated using this dataset, as they depended on the measurement object. The dataset analysis revealed that, for example, the results of the carborne survey were smaller than those of the other surveys because the field of view of the carborne survey was limited to paved roads. The location factor of different land uses was also evaluated considering the characteristics of the four survey methods. Nine years after the FDNPP accident, the location factor ranged from 0.26 to 0.49, while the half-life of the air dose rate ranged from 1.2 to 1.6.Conclusion: We found that the decreasing trend in the air dose rate of the FDNPP accident was similar to the results obtained after the Chernobyl accident. These parameters will be useful for the prediction of the future exposure dose at the post-accident.","PeriodicalId":36088,"journal":{"name":"Journal of Radiation Protection and Research","volume":"29 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80067387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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