Pub Date : 2023-07-06DOI: 10.15392/2319-0612.2023.2281
A. Khorshidi, M. Ashoor
Breast cancer is one of the most common malignant diseases in women. After tumor mass surgery, radiation therapy is regularly taken into account the gold standard for the treatment. Kilo to Mega voltage photons have been suggested due to their characteristic depth dose build-up regime, reducing the dose to the breast skin to a fraction of the maximum dose exposure. During treatment, mean glandular dose is commonly used as a criterion for identifying radiation risks. Here, two outlines in cubic-rectangular (CR) and cylindrical- taper (CT) outlines were modelled together with corresponding assumptions using Monte-Carlo simulation and the recorded absorbed dose ratio (ADR) values were compared via defined a positron source by 511 keV energy. The results showed that the amounts of absorption and scattering cross-sections next to the ADR amount decreased as the height of the CR outline decreased. The average dose ratio amount in the CR outline was reduced by about 96% compared to that in the CT outline. By increasing the positron source distance from the nipple, the ADR amounts decreased for both outlines. The amount of accumulated dose ratio decreased harshly in the CR outline rather than in the CT outline. This study can be useful to examine breast tissue deformity in treatment planning.
{"title":"New Deformity Outline on the Breast Radiation Therapy for diminishing Absorbed Dose Ratio","authors":"A. Khorshidi, M. Ashoor","doi":"10.15392/2319-0612.2023.2281","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2281","url":null,"abstract":"Breast cancer is one of the most common malignant diseases in women. After tumor mass surgery, radiation therapy is regularly taken into account the gold standard for the treatment. Kilo to Mega voltage photons have been suggested due to their characteristic depth dose build-up regime, reducing the dose to the breast skin to a fraction of the maximum dose exposure. During treatment, mean glandular dose is commonly used as a criterion for identifying radiation risks. Here, two outlines in cubic-rectangular (CR) and cylindrical- taper (CT) outlines were modelled together with corresponding assumptions using Monte-Carlo simulation and the recorded absorbed dose ratio (ADR) values were compared via defined a positron source by 511 keV energy. The results showed that the amounts of absorption and scattering cross-sections next to the ADR amount decreased as the height of the CR outline decreased. The average dose ratio amount in the CR outline was reduced by about 96% compared to that in the CT outline. By increasing the positron source distance from the nipple, the ADR amounts decreased for both outlines. The amount of accumulated dose ratio decreased harshly in the CR outline rather than in the CT outline. This study can be useful to examine breast tissue deformity in treatment planning.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89965882","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 : 2023-07-04DOI: 10.15392/2319-0612.2023.2175
J. Soares, Natasha Briggs e Silva, R. C. Curzio, Matheus Santos Martins, Magda Maia de Azevedo Tororó, Ary Machado de Azevedo, V. A. V. Ferreira, D. O. Cardoso, E. S. L. Oliveira, Antônio Pedro Júnior
The Argonauta research reactor at the Institute of Nuclear Engineering - IEN operates, under normal conditions, at powers ranging from 1.7 to 340 W, developing activities of a scientific-technological nature in the areas of neutron radiography, radionuclide production and conduction from experimental practices to graduate courses at CNEN research institutions and other Brazilian institutes of science and technology. During some security operations, the presence of investigators, students and/or operators inside and around the main hall of the Argonauta is required. Therefore, it is important to assess normal occupational exposure conditions when the reactor is in critical condition. This makes it possible to verify in greater detail the equivalent doses of ambient gamma radiation contained by the combustion of the fuel element inside the reactor room and in the surrounding areas, according to the Radiation Protection Plan (RPP) of this installation. In this work, a didactic activity was carried out to familiarize the students of the first period of the Master's Course in Nuclear Engineering, at the Military Institute of Engineering, with the procedures involved in the radiometric survey of the free, controlled and subsequent locations of this nuclear installation. This practice aims to identify the doses to which Occupationally Exposed Workers (OEW) and the general public are admitted, verifying compliance with regulatory requirements regarding the monitoring of environmental and local activities, as well as a comparison between the radiation monitors used.
{"title":"Comparison of the response of two scintillator detectors used in an environmental and occupational radiometric survey during the operation of the Argonauta reactor","authors":"J. Soares, Natasha Briggs e Silva, R. C. Curzio, Matheus Santos Martins, Magda Maia de Azevedo Tororó, Ary Machado de Azevedo, V. A. V. Ferreira, D. O. Cardoso, E. S. L. Oliveira, Antônio Pedro Júnior","doi":"10.15392/2319-0612.2023.2175","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2175","url":null,"abstract":"The Argonauta research reactor at the Institute of Nuclear Engineering - IEN operates, under normal conditions, at powers ranging from 1.7 to 340 W, developing activities of a scientific-technological nature in the areas of neutron radiography, radionuclide production and conduction from experimental practices to graduate courses at CNEN research institutions and other Brazilian institutes of science and technology. During some security operations, the presence of investigators, students and/or operators inside and around the main hall of the Argonauta is required. Therefore, it is important to assess normal occupational exposure conditions when the reactor is in critical condition. This makes it possible to verify in greater detail the equivalent doses of ambient gamma radiation contained by the combustion of the fuel element inside the reactor room and in the surrounding areas, according to the Radiation Protection Plan (RPP) of this installation. In this work, a didactic activity was carried out to familiarize the students of the first period of the Master's Course in Nuclear Engineering, at the Military Institute of Engineering, with the procedures involved in the radiometric survey of the free, controlled and subsequent locations of this nuclear installation. This practice aims to identify the doses to which Occupationally Exposed Workers (OEW) and the general public are admitted, verifying compliance with regulatory requirements regarding the monitoring of environmental and local activities, as well as a comparison between the radiation monitors used.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86926731","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 : 2023-07-03DOI: 10.15392/2319-0612.2023.2284
Eduardo Henrique Damasceno da Gama, Ricardo Kropf Santos Fermam
The purpose of this study is to identify the coverage of quality assurance program (QAP) to be applied on a Maintenance Naval Base to the Brazilian conventional nuclear-powered submarine. Based on literature review and documents collected at the Angra I nuclear power plant, located in Brazil, it was possible to determine the coverage of QAP for a Brazilian Naval Base that will perform maintenance services on a conventional nuclear-powered submarine. The data were complemented by 6 interviews with specialists from nuclear sector. Regarding the countries that have nuclear-powered submarines, QAP implemented in their Maintenance Bases are confidential information. Another finding, based on the field research, showed that the QAP existing at the Angra I surpassed the 13 requirements established by Standard CNEN-NN-1.16 (Quality Assurance for the Safety of NPP) and, according to the interviewees, can be adapted for the Naval Maintenance Base of the Brazilian Navy. Thus, this study points out 25 requirements that can be used for the establishment of a QAP for the Naval Base in the operation phase of the conventional nuclear-powered submarine; The lack of technical standards and academic literature on the development of QAP, this study can serve as a guideline for the development of a QAP for Maintenance Naval Bases of Nuclear Submarines by the countries interested in this military technology.
{"title":"Identification of coverage of quality assurance program for maintenance naval base to the Brazilian conventional nuclear-powered submarine","authors":"Eduardo Henrique Damasceno da Gama, Ricardo Kropf Santos Fermam","doi":"10.15392/2319-0612.2023.2284","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2284","url":null,"abstract":"The purpose of this study is to identify the coverage of quality assurance program (QAP) to be applied on a Maintenance Naval Base to the Brazilian conventional nuclear-powered submarine. Based on literature review and documents collected at the Angra I nuclear power plant, located in Brazil, it was possible to determine the coverage of QAP for a Brazilian Naval Base that will perform maintenance services on a conventional nuclear-powered submarine. The data were complemented by 6 interviews with specialists from nuclear sector. Regarding the countries that have nuclear-powered submarines, QAP implemented in their Maintenance Bases are confidential information. Another finding, based on the field research, showed that the QAP existing at the Angra I surpassed the 13 requirements established by Standard CNEN-NN-1.16 (Quality Assurance for the Safety of NPP) and, according to the interviewees, can be adapted for the Naval Maintenance Base of the Brazilian Navy. Thus, this study points out 25 requirements that can be used for the establishment of a QAP for the Naval Base in the operation phase of the conventional nuclear-powered submarine; The lack of technical standards and academic literature on the development of QAP, this study can serve as a guideline for the development of a QAP for Maintenance Naval Bases of Nuclear Submarines by the countries interested in this military technology.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81336648","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}
The severe acute respiratory syndrome coronavirus 2 pandemic started in the December of 2019 at China. The second wave of the pandemic in India peaked between April-May 2021. In order to reduce the transmission and infectivity of the virus several vaccines were approved for emergent use. Studies have shown the effectiveness of vaccination in reducing the clinical severity of infection by the corona virus. In this study we aim to assess the effect of vaccination on the computed tomography severity score (CTSS). The study included 140 patients who tested positive for COVID 19 on RT PCR or rapid antigen test. Seventy of these patients had received at least one dose of vaccination and 70 patients were unvaccinated. CT scan of the chest was done for all patients and a CTSS ranging from 0 to 25 was assigned depending on the extent of lobar involvement. We found that a higher percentage (72.86%) of unvaccinated patients had severe disease compared to the vaccinated group (38.57%), 5.71% of unvaccinated patients had mild disease compared to 30% of vaccinated patients. The difference between the two groups was found to be statistically significant. On comparing the CTSS of patients with and without vaccination in our study, we found a significant reduction in the severity scores in the vaccinated group. Through this study the vaccine’s efficacy could be validated objectively. This article aims to emphasize the role of vaccination in our fight against the pandemic caused by the corona virus.
{"title":"Effect of COVID 19 vaccination on the CT severity score for SARS CoV2 pneumonia- an experience from the initial wave.","authors":"Radhika Batra, Sneha Harish C, Swati Gupta, Anju Garg","doi":"10.15392/2319-0612.2023.2279","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2279","url":null,"abstract":"The severe acute respiratory syndrome coronavirus 2 pandemic started in the December of 2019 at China. The second wave of the pandemic in India peaked between April-May 2021. In order to reduce the transmission and infectivity of the virus several vaccines were approved for emergent use. Studies have shown the effectiveness of vaccination in reducing the clinical severity of infection by the corona virus. In this study we aim to assess the effect of vaccination on the computed tomography severity score (CTSS). The study included 140 patients who tested positive for COVID 19 on RT PCR or rapid antigen test. Seventy of these patients had received at least one dose of vaccination and 70 patients were unvaccinated. CT scan of the chest was done for all patients and a CTSS ranging from 0 to 25 was assigned depending on the extent of lobar involvement. We found that a higher percentage (72.86%) of unvaccinated patients had severe disease compared to the vaccinated group (38.57%), 5.71% of unvaccinated patients had mild disease compared to 30% of vaccinated patients. The difference between the two groups was found to be statistically significant. On comparing the CTSS of patients with and without vaccination in our study, we found a significant reduction in the severity scores in the vaccinated group. Through this study the vaccine’s efficacy could be validated objectively. This article aims to emphasize the role of vaccination in our fight against the pandemic caused by the corona virus.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90906341","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 : 2023-06-27DOI: 10.15392/2319-0612.2023.2276
Daniel Mol Machado, A. Mól, André Cotelli Santo, M. Vidal, C. Lapa
Ergonomic Analysis consists of making value judgments about the global performance of certain man-machine or man-task systems and may result from a demand related to conditions and/or safety at work. However, during the performance of the Ergonomic Analysis, the presence of ergonomists can interfere with the work progress, which limits the observation time. Organizations that have risk areas have already been using simulated exercises to train their professionals. With the use of simulation tools, it becomes increasingly necessary to develop methods and techniques that allow the performance of this training, as close as possible to real work activities. In this context, this article proposed to create and verify if the use of Virtual Reality can help the Ergonomic Analysis of Work, developing scenarios and virtual simulation environments, contextualized by the Ergonomics perspective. For this purpose, a case study was carried out at the Institute of Nuclear Engineering where the Ergonomic Work Analysis and the modeling of the virtual environment were carried out. Finally, from the results presented, it can be concluded that Virtual Reality serves as a complementary tool to assist the ergonomist in the Ergonomic Analysis process, allowing him to use the tool to reduce risks, saving time and improving his performance.
{"title":"The Use Virtual Reality to Assist In The Preparation Of An Ergonomic Analysis Of Nuclear Facilities","authors":"Daniel Mol Machado, A. Mól, André Cotelli Santo, M. Vidal, C. Lapa","doi":"10.15392/2319-0612.2023.2276","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2276","url":null,"abstract":"Ergonomic Analysis consists of making value judgments about the global performance of certain man-machine or man-task systems and may result from a demand related to conditions and/or safety at work. However, during the performance of the Ergonomic Analysis, the presence of ergonomists can interfere with the work progress, which limits the observation time. Organizations that have risk areas have already been using simulated exercises to train their professionals. With the use of simulation tools, it becomes increasingly necessary to develop methods and techniques that allow the performance of this training, as close as possible to real work activities. In this context, this article proposed to create and verify if the use of Virtual Reality can help the Ergonomic Analysis of Work, developing scenarios and virtual simulation environments, contextualized by the Ergonomics perspective. For this purpose, a case study was carried out at the Institute of Nuclear Engineering where the Ergonomic Work Analysis and the modeling of the virtual environment were carried out. Finally, from the results presented, it can be concluded that Virtual Reality serves as a complementary tool to assist the ergonomist in the Ergonomic Analysis process, allowing him to use the tool to reduce risks, saving time and improving his performance.\u0000 ","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73098701","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 : 2023-06-26DOI: 10.15392/2319-0612.2023.2275
D. Fungaro, L. Grosche, P. Silva
Flue gas desulfurization (FGD) waste is an industrial by-product generated during the flue gas desulfurization process in coal-fired power plants. This by-product contain trace quantities of naturally occurring radionuclides and elements such as As, Ba, Co, Cr, Zn. The characteristics of FGD waste are important for its reuse and are mainly depend on the desulfurization process. In this work, two types of FGD materials collected from three coal-fired power plants using semi-dry and wet processes were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), X-ray fluorescence (XFR) and particle size analysis. The radioactive content of 238U, 232Th, 228Th, 226Ra, 228Ra, 210Pb and 40K and trace elements were also determined using Neutron activation analysis and Gamma-ray spectrometry. The major constituents for all samples were Ca, Si, S, Al and Fe. Wet FGD by-product presented also high magnesium content. The wastes contain mainly semi-hydrate calcium sulfite and calcium sulfate. The particle size of FGD from semi-dry process was lower than that from the wet process. The average activity concentration of 238U, 232Th, 226Ra, 210Pb, 228Ra, 228Th and 40K varied between were 50-71, 33-42, 28-52, 113-150, 26-33, 33-39, 161-390 Bq kg-1, respectively. According to the results of leaching and solubilization tests, FGD samples were classified as non-hazardous and non-inert. The obtained data are useful for evaluation of possible applications of FGD by-products.
{"title":"Physicochemical and radiological characterization of flue gas desulfuration waste samples from Brazilian coal-fired power plants","authors":"D. Fungaro, L. Grosche, P. Silva","doi":"10.15392/2319-0612.2023.2275","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2275","url":null,"abstract":"Flue gas desulfurization (FGD) waste is an industrial by-product generated during the flue gas desulfurization process in coal-fired power plants. This by-product contain trace quantities of naturally occurring radionuclides and elements such as As, Ba, Co, Cr, Zn. The characteristics of FGD waste are important for its reuse and are mainly depend on the desulfurization process. In this work, two types of FGD materials collected from three coal-fired power plants using semi-dry and wet processes were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), X-ray fluorescence (XFR) and particle size analysis. The radioactive content of 238U, 232Th, 228Th, 226Ra, 228Ra, 210Pb and 40K and trace elements were also determined using Neutron activation analysis and Gamma-ray spectrometry. The major constituents for all samples were Ca, Si, S, Al and Fe. Wet FGD by-product presented also high magnesium content. The wastes contain mainly semi-hydrate calcium sulfite and calcium sulfate. The particle size of FGD from semi-dry process was lower than that from the wet process. The average activity concentration of 238U, 232Th, 226Ra, 210Pb, 228Ra, 228Th and 40K varied between were 50-71, 33-42, 28-52, 113-150, 26-33, 33-39, 161-390 Bq kg-1, respectively. According to the results of leaching and solubilization tests, FGD samples were classified as non-hazardous and non-inert. The obtained data are useful for evaluation of possible applications of FGD by-products.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73579231","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 : 2023-06-22DOI: 10.15392/2319-0612.2023.2249
Tallyson Sarmento Alvarenga, Simone . S. Fernandes, Walsan W. Pereira, Mike. R. Mayhughc, Linda V. E. Caldas
At the Neutron Calibration Laboratory (LCN) of IPEN/CNEN, a 241AmBe source was used to test and calibrate neutron detectors. The neutrons emitted by the source reach the detector as intended, but they also scatter undesirably from the building's floor, ceiling, and walls, leading to indirect detection. A Long Counter (LC) detector was modeled using the MCNPX Monte Carlo code. The objective of this study was to measure the contribution of scattered radiation at the LCN / IPEN, and to determine the fluence rate, at different points in the calibration room at source-to-detector distances of 100 cm and 150 cm; subsequently, the results were compared with those of the Brazilian Laboratory of Metrology of Ionizing Radiation (LNMRI). The results show that the fluence rates of LCN / IPEN are comparable to those of this neutron laboratory for the 100 and 150 cm source-to-detector distances using a 241AmBe source (37 GBq). The results show that the calibration of neutron detectors should be performed at distances less than 100 cm, where the contribution of scattered radiation is within the 40% limit recommended by ISO 8529-1.
{"title":"Estimation of scattered radiation influence on neutron beams at a calibration laboratory using Monte Carlo simulation of a long counter","authors":"Tallyson Sarmento Alvarenga, Simone . S. Fernandes, Walsan W. Pereira, Mike. R. Mayhughc, Linda V. E. Caldas","doi":"10.15392/2319-0612.2023.2249","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2249","url":null,"abstract":"At the Neutron Calibration Laboratory (LCN) of IPEN/CNEN, a 241AmBe source was used to test and calibrate neutron detectors. The neutrons emitted by the source reach the detector as intended, but they also scatter undesirably from the building's floor, ceiling, and walls, leading to indirect detection. A Long Counter (LC) detector was modeled using the MCNPX Monte Carlo code. The objective of this study was to measure the contribution of scattered radiation at the LCN / IPEN, and to determine the fluence rate, at different points in the calibration room at source-to-detector distances of 100 cm and 150 cm; subsequently, the results were compared with those of the Brazilian Laboratory of Metrology of Ionizing Radiation (LNMRI). The results show that the fluence rates of LCN / IPEN are comparable to those of this neutron laboratory for the 100 and 150 cm source-to-detector distances using a 241AmBe source (37 GBq). The results show that the calibration of neutron detectors should be performed at distances less than 100 cm, where the contribution of scattered radiation is within the 40% limit recommended by ISO 8529-1.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136177874","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 : 2023-06-21DOI: 10.15392/2319-0612.2023.2232
Andre Gonçalves Prospero, Ana Carolina Ferreira, Diana Rodrigues Pina, Antonio Cesar Pernomian, Wander De Oliveira
The Technical Report Series 398 (TRS-398), Electron Dosimetry Working Party (EWDP), and Task Group 51 (TG 51) are the most important protocols for reference dosimetry. In the case of electron beam reference dosimetry, these protocols recommend using parallel-plate ionization chambers for beams with R50 values below specific thresholds. However, recent papers suggested using cylindrical chambers for reference dosimetry of all electron beam energies. Here we compared different protocols using a cylindrical chamber with the recommendations of using a parallel-plate chamber and the TRS-398 formalism for the dosimetry of several electron beam energies. We employed electron beams with nominal energies of 4, 6, 9, 12, and 15 MeV of a Varian 2100C linear accelerator, an Exradin A12, and an Exradin P11 chamber for the analysis. The results showed differences below 3% when comparing the cylindrical chamber and alternative protocols with the parallel-plate chamber and the TRS-398 formalism for electron beams reference dosimetry. These results can bring confidence in using a cylindrical chamber for reference electron beam dosimetry, which can make the electron beam dosimetry procedure simpler and faster.
{"title":"Analysis of different protocols using an Exradin A12 cylindrical chamber for electron beam reference dosimetry","authors":"Andre Gonçalves Prospero, Ana Carolina Ferreira, Diana Rodrigues Pina, Antonio Cesar Pernomian, Wander De Oliveira","doi":"10.15392/2319-0612.2023.2232","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2232","url":null,"abstract":"The Technical Report Series 398 (TRS-398), Electron Dosimetry Working Party (EWDP), and Task Group 51 (TG 51) are the most important protocols for reference dosimetry. In the case of electron beam reference dosimetry, these protocols recommend using parallel-plate ionization chambers for beams with R50 values below specific thresholds. However, recent papers suggested using cylindrical chambers for reference dosimetry of all electron beam energies. Here we compared different protocols using a cylindrical chamber with the recommendations of using a parallel-plate chamber and the TRS-398 formalism for the dosimetry of several electron beam energies. We employed electron beams with nominal energies of 4, 6, 9, 12, and 15 MeV of a Varian 2100C linear accelerator, an Exradin A12, and an Exradin P11 chamber for the analysis. The results showed differences below 3% when comparing the cylindrical chamber and alternative protocols with the parallel-plate chamber and the TRS-398 formalism for electron beams reference dosimetry. These results can bring confidence in using a cylindrical chamber for reference electron beam dosimetry, which can make the electron beam dosimetry procedure simpler and faster.","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73993786","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 : 2023-06-19DOI: 10.15392/2319-0612.2023.2178
Fernando Rodrigues, A. Nolasco, Luiz Cláudio Meira Belo, Claudete R E Silva, T. Fonseca
Total body irradiation (TBI) is a treatment modality of radiotherapy. It can be used for immunosuppression of transplanted patients or for metastatic protocols. In this study, TBI was performed using the anthropomorphic Alderson-Rando phantom filled with thermoluminescent dosimeters (TLDs) and irradiated with a 6 MV photon beam from the Elekta linear accelerator in two different setups, one at the hospital São Francisco, BH, MG and second at the hospital Santa Casa in Lavras, MG. The dose distribution in the left and right lungs was estimated, analyzed, and compared with results from the literature. Our results showed that dose homogeneity is more adequate with dual-field irradiation.
全身照射(TBI)是放射治疗的一种治疗方式。它可用于移植患者的免疫抑制或转移方案。在这项研究中，使用充满热致发光剂量计(tld)的拟人Alderson-Rando幻体进行TBI，并在两个不同的设置中使用Elekta线性加速器的6 MV光子束照射，一个在密歇根州 o Francisco医院，第二个在密歇根州拉夫拉斯的Santa Casa医院。估计、分析左、右肺的剂量分布，并与文献结果进行比较。结果表明，双场辐照的剂量均匀性较好。
{"title":"Assessment of dose heterogeneity in TBI using the thorax of the anthropomorphic Alderson-Rando phantom and TLDs in two different setups","authors":"Fernando Rodrigues, A. Nolasco, Luiz Cláudio Meira Belo, Claudete R E Silva, T. Fonseca","doi":"10.15392/2319-0612.2023.2178","DOIUrl":"https://doi.org/10.15392/2319-0612.2023.2178","url":null,"abstract":"Total body irradiation (TBI) is a treatment modality of radiotherapy. It can be used for immunosuppression of transplanted patients or for metastatic protocols. In this study, TBI was performed using the anthropomorphic Alderson-Rando phantom filled with thermoluminescent dosimeters (TLDs) and irradiated with a 6 MV photon beam from the Elekta linear accelerator in two different setups, one at the hospital São Francisco, BH, MG and second at the hospital Santa Casa in Lavras, MG. The dose distribution in the left and right lungs was estimated, analyzed, and compared with results from the literature. Our results showed that dose homogeneity is more adequate with dual-field irradiation.\u0000 ","PeriodicalId":9203,"journal":{"name":"Brazilian Journal of Radiation Sciences","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87880018","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 : 2023-06-16DOI: 10.15392/2319-0612.2023.2131
A. J. González, L. Sanchez, A. Torres, A. Machado
Image-guided interventional procedures have become one of the medical applications that produces the highest doses of radiation for both the patient and the personnel involved in it. Safety assessment was applied to a generic service where image-guided interventional procedures was carried, using the semi-quantitative method of risk matrix, implemented in the Cuban SECURE-MR-FMEA code. The process map was prepared, identifying 6 stages with 76 accidental sequences. Values showed that the first screening for the developed model reports 45 % of high risks, 42% and 13 % of moderate and low risks, and once the number of controllers increased, high risks decrease to 11 % and there is an increase in moderate and low risks of 54 % and 35 % respectively. These results stress the importance of using all necessary measures for the protection of the public, patients and occupationally exposed workers.
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