Pub Date : 2023-04-27DOI: 10.15392/2319-0612.2023.2241
Ana Luiza Milani, A. F. Alves, Matheus Alvarez, S. P. Souza, Túlio Guilherme Soares Marques, Marcos Aureliano Araújo Silva, J. T. Trindade Filho, Diana Rodrigues Pina
Computed tomography exams are considered diagnostic imaging exams that generate significant radiation dose to the patient. Justification, optimization, and dose limitation are radiological protection principles used to minimize patient and staff exposure, ensuring the quality of the service provided. The objective of this study was to analyze CT scan data, analyzing the number of exams, the patients' effective cumulated dose, and the repeatability of the exams. The study data covers the 2013 to 2022 period during which a progressive increase was observed in the number of exams performed over time, with exams doubling in this period. The most used Computed Tomography protocols were brain/skull (27.4%), pelvis (17.3%), and abdomen (13.7%) during the study period. Approximately 76.3% of patients have a cumulative dose of less than 25 mSv, while about 1% accumulated more than 100 mSv. The repeatability of CT scans for the same patient over a short period varies, reaching until 17 scans in 30 days for a single patient. The results indicated a necessity to develop strategies for individual dose management methods for the institution’s internal practices. An intervention could be implemented by creating periodically updated handouts and guidelines based on professionals' knowledge.
{"title":"Analysis of repeated computed tomography scans and cumulative effective dose of patients in a hospital","authors":"Ana Luiza Milani, A. F. Alves, Matheus Alvarez, S. P. Souza, Túlio Guilherme Soares Marques, Marcos Aureliano Araújo Silva, J. T. Trindade Filho, Diana Rodrigues Pina","doi":"10.15392/2319-0612.2023.2241","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2241","url":null,"abstract":"Computed tomography exams are considered diagnostic imaging exams that generate significant radiation dose to the patient. Justification, optimization, and dose limitation are radiological protection principles used to minimize patient and staff exposure, ensuring the quality of the service provided. The objective of this study was to analyze CT scan data, analyzing the number of exams, the patients' effective cumulated dose, and the repeatability of the exams. The study data covers the 2013 to 2022 period during which a progressive increase was observed in the number of exams performed over time, with exams doubling in this period. The most used Computed Tomography protocols were brain/skull (27.4%), pelvis (17.3%), and abdomen (13.7%) during the study period. Approximately 76.3% of patients have a cumulative dose of less than 25 mSv, while about 1% accumulated more than 100 mSv. The repeatability of CT scans for the same patient over a short period varies, reaching until 17 scans in 30 days for a single patient. The results indicated a necessity to develop strategies for individual dose management methods for the institution’s internal practices. An intervention could be implemented by creating periodically updated handouts and guidelines based on professionals' knowledge.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85918917","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 : 2023-04-13DOI: 10.15392/2319-0612.2023.2240
B. G. A. Schirmer, E. V. Santos, J. M. Pereira, N. V. S. Cardoso, R. D. B. Dias de Brito Oliveira, C. Malamut
The use of mouse and rat models in conjunction with anatomic functional imaging techniques has directly contributed to expanding knowledge about the complex pathophysiology of stroke. Therefore, this study aims to identify the most relevant mouse and rat models of stroke and how [18F]FDG/PET can contribute to this pathology study. A narrative review of the literature was performed to describe applications of positron emission tomography in conjunction with the radiopharmaceutical [18F]FDG in stroke models. PubMed, Scopus, and Web of Science were searched for relevant articles published between 2015 and 2022. In this study, we describe applications of positron emission tomography in combination with the radiopharmaceutical [18F]FDG in mouse and rat stroke models. The most commonly used model was middle cerebral artery occlusion (MCAO) in rats. This study demonstrates that using murine and rat models in conjunction with anatomic functional imaging techniques has directly contributed to expanding knowledge about the complex pathophysiology of stroke. In addition, they have been essential for studies aimed at discovering and developing therapeutic and prophylactic strategies for the disease.
使用小鼠和大鼠模型结合解剖功能成像技术，直接有助于扩大对中风复杂病理生理学的认识。因此，本研究旨在确定与脑卒中最相关的小鼠和大鼠模型，以及[18F]FDG/PET如何参与该病理研究。对文献进行了叙述性回顾，以描述正电子发射断层扫描与放射性药物[18F]FDG在中风模型中的应用。检索了PubMed、Scopus和Web of Science在2015年至2022年间发表的相关文章。在这项研究中，我们描述了正电子发射断层扫描结合放射性药物[18F]FDG在小鼠和大鼠中风模型中的应用。大鼠最常用的模型是大脑中动脉闭塞(MCAO)。这项研究表明，将小鼠和大鼠模型与解剖功能成像技术相结合，直接有助于扩大对中风复杂病理生理学的了解。此外，它们对于旨在发现和制定该疾病的治疗和预防战略的研究至关重要。
{"title":"[18F]FDG/PET: a non-invasive technique for the study of stroke in murine and rat models","authors":"B. G. A. Schirmer, E. V. Santos, J. M. Pereira, N. V. S. Cardoso, R. D. B. Dias de Brito Oliveira, C. Malamut","doi":"10.15392/2319-0612.2023.2240","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2240","url":null,"abstract":"The use of mouse and rat models in conjunction with anatomic functional imaging techniques has directly contributed to expanding knowledge about the complex pathophysiology of stroke. Therefore, this study aims to identify the most relevant mouse and rat models of stroke and how [18F]FDG/PET can contribute to this pathology study. A narrative review of the literature was performed to describe applications of positron emission tomography in conjunction with the radiopharmaceutical [18F]FDG in stroke models. PubMed, Scopus, and Web of Science were searched for relevant articles published between 2015 and 2022. In this study, we describe applications of positron emission tomography in combination with the radiopharmaceutical [18F]FDG in mouse and rat stroke models. The most commonly used model was middle cerebral artery occlusion (MCAO) in rats. This study demonstrates that using murine and rat models in conjunction with anatomic functional imaging techniques has directly contributed to expanding knowledge about the complex pathophysiology of stroke. In addition, they have been essential for studies aimed at discovering and developing therapeutic and prophylactic strategies for the disease.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83289110","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 : 2023-04-11DOI: 10.15392/2319-0612.2023.2187
When handling unsealed radioactive sources, radiological protection attention must be taken to avoid unnecessary exposure and radioactive contaminations, and an important and necessary practice to prevent such contaminations is the use of gloves when handling these sources. The present work aimed to determine the effectiveness of contamination protection provided by different types of disposable polymeric gloves used in Nuclear Medicine Service in Clinic Hospital of Porto Alegre, testing the main radiopharmaceuticals used at this site: [99mTc]sodium pertechnetate, [18F]FDG and [131I]sodium iodide. The analysis was performed using the wipe test inside gloves intentionally contaminated on the outside with these radiopharmaceuticals. The radiation detector used to measure the contamination was a NaI(Tl) scintillator well-type counter. The results indicate that three types of gloves analyzed protect the user from [99mTc]sodium pertechnetate and [18F]FDG contamination, for permanence times with the glove after contamination for up to 15 min (interval tested). For [131I]sodium iodide, gloves are completely effective in protection as long as they are used for a time interval after contamination of the external surface of up to: Latex – 5 min; Vinyl – 5 min; Nitrile – 10 min. Among them, the nitrile glove are the most effective, since contamination was not observed on the inner face for times equal to or less than 10 min; and, for an interval of 15 min, the percentage of permeation obtained was lower than the other two types: 3.3 times lower than vinyl glove permeation and 1.3 times lower of the latex glove permeation. It was also possible to estimate the skin dose rate due to contamination caused by iodine permeation for each glove case and time tested.
{"title":"Effectiveness of polymeric gloves in radioprotection against contamination in nuclear medicine","authors":"","doi":"10.15392/2319-0612.2023.2187","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2187","url":null,"abstract":"When handling unsealed radioactive sources, radiological protection attention must be taken to avoid unnecessary exposure and radioactive contaminations, and an important and necessary practice to prevent such contaminations is the use of gloves when handling these sources. The present work aimed to determine the effectiveness of contamination protection provided by different types of disposable polymeric gloves used in Nuclear Medicine Service in Clinic Hospital of Porto Alegre, testing the main radiopharmaceuticals used at this site: [99mTc]sodium pertechnetate, [18F]FDG and [131I]sodium iodide. The analysis was performed using the wipe test inside gloves intentionally contaminated on the outside with these radiopharmaceuticals. The radiation detector used to measure the contamination was a NaI(Tl) scintillator well-type counter. The results indicate that three types of gloves analyzed protect the user from [99mTc]sodium pertechnetate and [18F]FDG contamination, for permanence times with the glove after contamination for up to 15 min (interval tested). For [131I]sodium iodide, gloves are completely effective in protection as long as they are used for a time interval after contamination of the external surface of up to: Latex – 5 min; Vinyl – 5 min; Nitrile – 10 min. Among them, the nitrile glove are the most effective, since contamination was not observed on the inner face for times equal to or less than 10 min; and, for an interval of 15 min, the percentage of permeation obtained was lower than the other two types: 3.3 times lower than vinyl glove permeation and 1.3 times lower of the latex glove permeation. It was also possible to estimate the skin dose rate due to contamination caused by iodine permeation for each glove case and time tested.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79980845","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 : 2023-04-03DOI: 10.15392/2319-0612.2023.2228
R. Lamour, M. Wasserman, E. Rochedo, J. Lugon Junior
This work is aiming at estimating the radiation doses to members of the public in case of an emergency exposure situation related to a hypothetical uranium mining tailings dam rupture at the UDC - Decommissioning Unit of Caldas, MG, Brazil. The calculations will help to managing the exposures of emergency workers and residents in the region downstream the dam. The computer code chosen to perform the simulations was FLO-2D@ software. Due to the uncertainties involved, mainly regarding the waste rheology and activity concentrations and in parameters values to be used in the dose assessment, considerations were made for the study to present results derived from conservative assumptions. Through the creation of flood maps, it was possible to estimate the extent of the areas affected by the released materials. The results showed that in a scenario of the tailings dam breach, deposition of mud shall extend over 20 km downstream affecting an area of nearly 3 km2. Total dose for a member of the public living in most affected areas would be around 43 mSv/y in the early phase after the accident. Although only shielding would be recommended under current radiation protection regulation, evacuation/relocation is suggested due to the presence of long-lived radionuclides. This protective measure would probably already be indicated by the accident itself, regardless of radiological reasons. More realistic assessment should be performed before returning people, considering long-term environmental transport and uses of the area. It must also be considered that long-term exposures have more restricted recommended acceptable levels than those for the emergency phase.
{"title":"Assessment of the environmental radiological impact in the emergency exposure phase through the simulation of a uranium mining tailings dam breach","authors":"R. Lamour, M. Wasserman, E. Rochedo, J. Lugon Junior","doi":"10.15392/2319-0612.2023.2228","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2228","url":null,"abstract":"This work is aiming at estimating the radiation doses to members of the public in case of an emergency exposure situation related to a hypothetical uranium mining tailings dam rupture at the UDC - Decommissioning Unit of Caldas, MG, Brazil. The calculations will help to managing the exposures of emergency workers and residents in the region downstream the dam. The computer code chosen to perform the simulations was FLO-2D@ software. Due to the uncertainties involved, mainly regarding the waste rheology and activity concentrations and in parameters values to be used in the dose assessment, considerations were made for the study to present results derived from conservative assumptions. Through the creation of flood maps, it was possible to estimate the extent of the areas affected by the released materials. The results showed that in a scenario of the tailings dam breach, deposition of mud shall extend over 20 km downstream affecting an area of nearly 3 km2. Total dose for a member of the public living in most affected areas would be around 43 mSv/y in the early phase after the accident. Although only shielding would be recommended under current radiation protection regulation, evacuation/relocation is suggested due to the presence of long-lived radionuclides. This protective measure would probably already be indicated by the accident itself, regardless of radiological reasons. More realistic assessment should be performed before returning people, considering long-term environmental transport and uses of the area. It must also be considered that long-term exposures have more restricted recommended acceptable levels than those for the emergency phase.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91400844","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 : 2023-03-29DOI: 10.15392/2319-0612.2023.2185
C. Sampaio, M. M. Martins, W. O. Sousa
According to the limit of detection (DL) presented in ISO 11929:2010, the International Organization for Standardization (ISO) abandoned the concept of minimum detectable amount (MDA) described in ISO 12790-1:2001. In this work we demonstrate and discuss how we calculate the detection limit for the determination of 210Pb by liquid scintillation counter (LSC) for the previously developed methodology and compare its results with the MDA value. The DL value found was 0.033 Bq/L instead of 0.032 Bq/L for MDA. The MDA and LD values did not differ virtually, the results highlight that the main change between the two Standard is related to the definition approach.
{"title":"Detection limit calculation according to ISO 11929 for in vitro 210Pb radiobioassay determinations by LSC","authors":"C. Sampaio, M. M. Martins, W. O. Sousa","doi":"10.15392/2319-0612.2023.2185","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2185","url":null,"abstract":"According to the limit of detection (DL) presented in ISO 11929:2010, the International Organization for Standardization (ISO) abandoned the concept of minimum detectable amount (MDA) described in ISO 12790-1:2001. In this work we demonstrate and discuss how we calculate the detection limit for the determination of 210Pb by liquid scintillation counter (LSC) for the previously developed methodology and compare its results with the MDA value. The DL value found was 0.033 Bq/L instead of 0.032 Bq/L for MDA. The MDA and LD values did not differ virtually, the results highlight that the main change between the two Standard is related to the definition approach.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85565012","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 : 2023-03-28DOI: 10.15392/2319-0612.2023.2119
K.C.W. Consatti, W. S. Santos, J. V. Valença, M. Yoshizumi
In radiology, knowing the X-ray spectrum characteristics makes it possible to estimate the absorbed dose in the patient and to improve image quality. In this study, an X-ray generator was proposed using the MCNPX code and to validate it, the simulated spectrum was compared to the data provided from AAPM Task Group 195, which resulted in a percentage difference of 8.7%. Furthermore, several X-ray spectra were generated and compared to the spectra obtained from commercially available softwares as xpecgen and SpekCalc. The percentage differences were of the order of 13% in comparison with SpekCalc and 8% with xpecgen. The major differences obtained between those spectra were concentrated in the region of characteristic peaks, independently if variations in electron beam energy, target angle or filtration thickness were performed.
在放射学中，了解x射线光谱特征可以估计患者的吸收剂量，提高图像质量。在本研究中，使用MCNPX代码提出了一个x射线发生器，并将模拟的光谱与AAPM Task Group 195提供的数据进行了比较，结果显示其百分比差异为8.7%。此外，生成了几个x射线光谱，并与商用软件(如expecgen和SpekCalc)获得的光谱进行了比较。与SpekCalc相比，百分比差异约为13%，与expecgen相比为8%。这些光谱之间的主要差异集中在特征峰区域，如果进行电子束能量、目标角度或过滤厚度的变化，则它们之间的差异是独立的。
{"title":"Validation and study of different parameters in the simulation of diagnostic X-ray spectra using the MCNPX code","authors":"K.C.W. Consatti, W. S. Santos, J. V. Valença, M. Yoshizumi","doi":"10.15392/2319-0612.2023.2119","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2119","url":null,"abstract":"In radiology, knowing the X-ray spectrum characteristics makes it possible to estimate the absorbed dose in the patient and to improve image quality. In this study, an X-ray generator was proposed using the MCNPX code and to validate it, the simulated spectrum was compared to the data provided from AAPM Task Group 195, which resulted in a percentage difference of 8.7%. Furthermore, several X-ray spectra were generated and compared to the spectra obtained from commercially available softwares as xpecgen and SpekCalc. The percentage differences were of the order of 13% in comparison with SpekCalc and 8% with xpecgen. The major differences obtained between those spectra were concentrated in the region of characteristic peaks, independently if variations in electron beam energy, target angle or filtration thickness were performed.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89477039","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 : 2023-03-24DOI: 10.15392/2319-0612.2023.2107
P. Gasparian, A. Malthez, L. Mariano, L. Campos, R. Politano
Since its discovery, ionizing radiation has been used in many different applications. Materials and methods have been developed to measure and quantify radiation doses. Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) are two techniques used for radiation dosimetry. Both TL and OSL are primarily applied in several areas, such as dating of ancient materials, equipment quality control and individual monitoring. One of the parameters to measure the knowledge and development of a technology is the number of patents related to the field. In this work, we established a methodology for patent search on the World Intellectual Property Organization (WIPO) database aiming to review the development of TL and OSL dosimetry over time. We concluded that along with the OSL technique development, the TL technique should continue to be explored in radiation dosimetry.
{"title":"An overview study on the TL and OSL dosimetry patent processes over time","authors":"P. Gasparian, A. Malthez, L. Mariano, L. Campos, R. Politano","doi":"10.15392/2319-0612.2023.2107","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2107","url":null,"abstract":"Since its discovery, ionizing radiation has been used in many different applications. Materials and methods have been developed to measure and quantify radiation doses. Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) are two techniques used for radiation dosimetry. Both TL and OSL are primarily applied in several areas, such as dating of ancient materials, equipment quality control and individual monitoring. One of the parameters to measure the knowledge and development of a technology is the number of patents related to the field. In this work, we established a methodology for patent search on the World Intellectual Property Organization (WIPO) database aiming to review the development of TL and OSL dosimetry over time. We concluded that along with the OSL technique development, the TL technique should continue to be explored in radiation dosimetry.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89281902","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 : 2023-03-22DOI: 10.15392/2319-0612.2023.2104
W. S. Santos, C. J. Santos, L. P. Neves, W. Belinato, M. R. Soares, J. V. Valença, A. Perini
In this work, the Monte Carlo MCNPX (2.7.0) code was used to evaluate the radioprotective properties of ten ornamental granitic samples produced in Brazil. For each sample of granite, the mass attenuation coefficient (µ/ρ) and half-value layer (HVL) were evaluated using the photon energy emitted by the following radioisotopes: 241Am (59,5 keV), 133Ba (356 keV), 137Cs (662 keV), 60Co (1250 keV), and 22Na (1274 keV). The MCNPX results showed agreement with the values obtained by using the XCOM database, as well as with theoretical and experimental results, available on the literature. The computational model built in this work can be used by the scientific community interested in parameters involving new materials for gamma radiation shielding, which has been used in different areas of the nuclear sciences.
{"title":"Evaluation of the radiation shielding properties of ornamental rocks produced in Brazil: A Monte Carlo approach","authors":"W. S. Santos, C. J. Santos, L. P. Neves, W. Belinato, M. R. Soares, J. V. Valença, A. Perini","doi":"10.15392/2319-0612.2023.2104","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2104","url":null,"abstract":"In this work, the Monte Carlo MCNPX (2.7.0) code was used to evaluate the radioprotective properties of ten ornamental granitic samples produced in Brazil. For each sample of granite, the mass attenuation coefficient (µ/ρ) and half-value layer (HVL) were evaluated using the photon energy emitted by the following radioisotopes: 241Am (59,5 keV), 133Ba (356 keV), 137Cs (662 keV), 60Co (1250 keV), and 22Na (1274 keV). The MCNPX results showed agreement with the values obtained by using the XCOM database, as well as with theoretical and experimental results, available on the literature. The computational model built in this work can be used by the scientific community interested in parameters involving new materials for gamma radiation shielding, which has been used in different areas of the nuclear sciences.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89706255","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 : 2023-03-14DOI: 10.15392/2319-0612.2023.2158
Fabiana Trevisan, B. Nascimento, Gabriel Chibana, Luciana Maeda, M. Vila, V. Yoshida, N. Aranha, V. Balcão, J. O. Oliveira Júnior
Purpose. This work aimed at evaluating the possibility of performing renal exams of dynamic renal (DRS) and static renal (SRS) scintigraphy on the same day (one-day protocol, ODP), exams that are currently performed in two days. Approach. 25 infants (50 kidneys) of both genders, aged 8.4 ± 5.9 years, underwent an F+20 DRS protocol with [99mTc]TcDTPA2- followed by [99mTc]TcDMSA2- administration for the performance of SRS images at 3, 6 and 24 h. Dynamic images (DRS) were classified as dilated (D), undetermined (U), and non-dilated (P). Static images (SRS) were classified as: depressed in accented degree (DA); depressed in moderate degree (DM); depressed in mild degree (DL) and normal (NL). Results. Out of the 25 patients (50 kidneys), 7 (14 kidneys) were excluded by functional exclusion, hence 18 patients (36 kidneys) were clinically compared regarding their static images after 3, 6 and 24 h, resulting in 33.0% of dilated and 66.7% non-dilated. Only two patients of the dilated group were classified as obstructed. At the group with non-dilated and dilated but non-obstructed kidneys, 100% of them had the same clinical classification at 6 and 24 h images. Conclusions. Performance of both DRS and SRS exams in a single day for pediatric patients, when medical requests are carried out jointly, is feasible in a population with or without dilatation, when the difference between dynamic and static images is of at least 6 h. Due to the small number of obstructed kidneys in this study, further evaluation in this population is needed.
{"title":"A feasibility study for a new one-day protocol for [99mTc]TcDTPA2- and [99mTc]TcDMSA2- renal scintigraphy on dilated and non-dilated pediatric patients: underlying rationale","authors":"Fabiana Trevisan, B. Nascimento, Gabriel Chibana, Luciana Maeda, M. Vila, V. Yoshida, N. Aranha, V. Balcão, J. O. Oliveira Júnior","doi":"10.15392/2319-0612.2023.2158","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2158","url":null,"abstract":"Purpose. This work aimed at evaluating the possibility of performing renal exams of dynamic renal (DRS) and static renal (SRS) scintigraphy on the same day (one-day protocol, ODP), exams that are currently performed in two days. Approach. 25 infants (50 kidneys) of both genders, aged 8.4 ± 5.9 years, underwent an F+20 DRS protocol with [99mTc]TcDTPA2- followed by [99mTc]TcDMSA2- administration for the performance of SRS images at 3, 6 and 24 h. Dynamic images (DRS) were classified as dilated (D), undetermined (U), and non-dilated (P). Static images (SRS) were classified as: depressed in accented degree (DA); depressed in moderate degree (DM); depressed in mild degree (DL) and normal (NL). Results. Out of the 25 patients (50 kidneys), 7 (14 kidneys) were excluded by functional exclusion, hence 18 patients (36 kidneys) were clinically compared regarding their static images after 3, 6 and 24 h, resulting in 33.0% of dilated and 66.7% non-dilated. Only two patients of the dilated group were classified as obstructed. At the group with non-dilated and dilated but non-obstructed kidneys, 100% of them had the same clinical classification at 6 and 24 h images. Conclusions. Performance of both DRS and SRS exams in a single day for pediatric patients, when medical requests are carried out jointly, is feasible in a population with or without dilatation, when the difference between dynamic and static images is of at least 6 h. Due to the small number of obstructed kidneys in this study, further evaluation in this population is needed.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73562843","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 : 2023-03-09DOI: 10.15392/2319-0612.2023.2243
J. W. Vieira, Pedro Henrique Avelino Andrade, A. C. H. Oliveira, V. Lima, Isabelle Viviane Batista de Lacerda, Arykerne Casado Silva, Ivan Eufrázio Santana, Whoody Alem Wanderley Farias, Larissa Cristina Silva dos Santos, Fernanda Gonçalves Oliveira, F. Lima
To evaluate the amount of energy deposited in radiosensitive organs and tissues of the human body, when an anthropomorphic phantom is irradiated, researchers in numerical dosimetry use the so-called exposure computational models (ECMs). One can imagine an ECM as a virtual scene composed of a phantom in a mathematically defined position in relation to a radioactive source. The source in these ECMs produces the initial state of the simulation: the position, direction, and energy with which each particle enters the phantom are essential variables. For subsequent states of a particle history, robust Monte Carlo (MC) codes are used. For the subsequent states of a particle's history, robust Monte Carlo (MC) codes are used, which simulate the average free path that the particle performs without interacting, its interaction with the atoms in the medium and the amount of energy deposited per interaction. MC codes also evaluate normalization quantities, so the results are printed in text files in the form of conversion coefficients between the absorbed dose and the selected normalization quantity. From the 2000s, the authors have published ECMs where a voxel phantom is irradiated by photons in the environment of the MC code EGSnrc (EGS = Electron Gamma Shower; nrc = National Research Council Canada). The production of articles, dissertations and theses required the use of specific computational tools, such as the FANTOMAS, DIP (Digital Image Processing) and Monte Carlo applications, for the various steps of numerical dosimetry, which ranges from the preparation of input files to the execution from the ECM to the organization and graphical and numerical analysis of the results. This article reviews computational phantoms for dosimetry mainly those produced in DEN-UFPE dissertations and thesis.
为了评估在人体的辐射敏感器官和组织中沉积的能量，当一个拟人化的幻影被照射时，数值剂量学的研究人员使用了所谓的暴露计算模型(ecm)。我们可以把ECM想象成一个虚拟场景，由一个与放射源相关的数学定义位置的幻影组成。这些ecm中的源产生模拟的初始状态:每个粒子进入幻影的位置、方向和能量是基本变量。对于粒子历史的后续状态，采用鲁棒蒙特卡罗(MC)码。对于粒子历史的后续状态，使用鲁棒蒙特卡罗(MC)代码，模拟粒子在没有相互作用的情况下的平均自由路径，它与介质中原子的相互作用以及每次相互作用所沉积的能量。MC代码还评估归一化量，因此结果以吸收剂量与所选归一化量之间的转换系数的形式打印在文本文件中。从2000年代开始，作者发表了ecm，其中体素幻影在MC代码EGSnrc (EGS = Electron Gamma Shower;加拿大国家研究委员会。文章、论文和论文的制作需要使用特定的计算工具，如FANTOMAS、DIP(数字图像处理)和蒙特卡罗应用程序，用于数值剂量学的各个步骤，从准备输入文件到执行ECM，再到组织和结果的图形和数值分析。本文主要综述了DEN-UFPE学位论文和论文中有关剂量学的计算模型。
{"title":"Development of anthropomorphic computational phantoms at the UFPE","authors":"J. W. Vieira, Pedro Henrique Avelino Andrade, A. C. H. Oliveira, V. Lima, Isabelle Viviane Batista de Lacerda, Arykerne Casado Silva, Ivan Eufrázio Santana, Whoody Alem Wanderley Farias, Larissa Cristina Silva dos Santos, Fernanda Gonçalves Oliveira, F. Lima","doi":"10.15392/2319-0612.2023.2243","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2243","url":null,"abstract":"To evaluate the amount of energy deposited in radiosensitive organs and tissues of the human body, when an anthropomorphic phantom is irradiated, researchers in numerical dosimetry use the so-called exposure computational models (ECMs). One can imagine an ECM as a virtual scene composed of a phantom in a mathematically defined position in relation to a radioactive source. The source in these ECMs produces the initial state of the simulation: the position, direction, and energy with which each particle enters the phantom are essential variables. For subsequent states of a particle history, robust Monte Carlo (MC) codes are used. For the subsequent states of a particle's history, robust Monte Carlo (MC) codes are used, which simulate the average free path that the particle performs without interacting, its interaction with the atoms in the medium and the amount of energy deposited per interaction. MC codes also evaluate normalization quantities, so the results are printed in text files in the form of conversion coefficients between the absorbed dose and the selected normalization quantity. From the 2000s, the authors have published ECMs where a voxel phantom is irradiated by photons in the environment of the MC code EGSnrc (EGS = Electron Gamma Shower; nrc = National Research Council Canada). The production of articles, dissertations and theses required the use of specific computational tools, such as the FANTOMAS, DIP (Digital Image Processing) and Monte Carlo applications, for the various steps of numerical dosimetry, which ranges from the preparation of input files to the execution from the ECM to the organization and graphical and numerical analysis of the results. This article reviews computational phantoms for dosimetry mainly those produced in DEN-UFPE dissertations and thesis.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80872689","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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