Pub Date : 2024-10-04DOI: 10.1016/j.radphyschem.2024.112279
Li Fu, Kaiyong Tang, Zungang Wang, Siyuan Zhang, Yan Zeng, Mo Zhou, HaiJun Li
LiMgPO4:Tb,Sm,B is a promising material for dosimetry applications, particularly in optically stimulated luminescence (OSL). This study aimed to explore residual thermoluminescence (R-TL) glow curves after different light bleaching times to establish a connection between TL traps and OSL components for the first time. The OSL decay curves and R-TL glow curve intensities were analyzed using exponential decay functions to account for optical decay, enabling identification of the OSL components and bleaching decay rates of each TL peak. A correlation between the decay rates of OSL components and bleaching decay rates of TL peaks, as well as the relationship between increased OSL intensity and decreased TL intensity were studied for different irradiation doses. Various bleaching models were evaluated to determine the most appropriate one for LiMgPO4:Tb,Sm,B. A non-thermally sensitive deep electron trap is proposed to enhance the understanding of the luminescence mechanism in LiMgPO4:Tb,Sm,B.
{"title":"Correlation between thermoluminescence and optically stimulated luminescence of LiMgPO4:Tb,Sm,B phosphor","authors":"Li Fu, Kaiyong Tang, Zungang Wang, Siyuan Zhang, Yan Zeng, Mo Zhou, HaiJun Li","doi":"10.1016/j.radphyschem.2024.112279","DOIUrl":"10.1016/j.radphyschem.2024.112279","url":null,"abstract":"<div><div>LiMgPO<sub>4</sub>:Tb,Sm,B is a promising material for dosimetry applications, particularly in optically stimulated luminescence (OSL). This study aimed to explore residual thermoluminescence (R-TL) glow curves after different light bleaching times to establish a connection between TL traps and OSL components for the first time. The OSL decay curves and R-TL glow curve intensities were analyzed using exponential decay functions to account for optical decay, enabling identification of the OSL components and bleaching decay rates of each TL peak. A correlation between the decay rates of OSL components and bleaching decay rates of TL peaks, as well as the relationship between increased OSL intensity and decreased TL intensity were studied for different irradiation doses. Various bleaching models were evaluated to determine the most appropriate one for LiMgPO<sub>4</sub>:Tb,Sm,B. A non-thermally sensitive deep electron trap is proposed to enhance the understanding of the luminescence mechanism in LiMgPO<sub>4</sub>:Tb,Sm,B.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"226 ","pages":"Article 112279"},"PeriodicalIF":2.8,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-03DOI: 10.1016/j.radphyschem.2024.112281
G. Hoşgör, E. Tabar, E. Kemah, H. Yakut
This paper aims to study the radiation shielding properties of lanthanide glasses, according to the formula xTiO2-51La2O3-(24-x) B2O3–8Gd2O3-8Nb2O5-6ZrO2-3SiO2 (x= 0, 4, 8, 12, 16, wt.%). Using FLUKA Monte Carlo code, the mass attenuation coefficients (MAC), half-value layers (HVL), and effective atomic numbers (Zeff) of the lanthanide glasses were estimated at medical diagnostic energies (between 20 and 150 keV). The MACs of the glasses are between 0.5183 and 24.407 cm2/g for 0Ti, 0.5215-24.788 cm2/g for 4Ti, 0.5193-25.161 cm2/g for 8Ti, 0.5163-25.529 cm2/g for 12Ti, and 0.5183-25.916 cm2/g for 16Ti. These results are consistent with the Phy-X theoretical database (with a percentage difference below 3 %). The lanthanide glasses showed good photon shielding ability compared to lead concrete, and RS-360 & RS-253-G18 commercial glasses, commonly used shielding materials. In this work, 16Ti possesses the highest, lowest, and highest values of MAC, HVL, and Zeff, respectively, at the various energies investigated, which implies that the 16Ti sample has better shielding performance. All in all, this work demonstrated that adding TiO2 to the glass samples could provide preferable shielding features.
{"title":"Influence of TiO2 content on the radiation shielding properties of the La2O3-B2O3-Gd2O3-Nb2O5-ZrO2-SiO2 glasses","authors":"G. Hoşgör, E. Tabar, E. Kemah, H. Yakut","doi":"10.1016/j.radphyschem.2024.112281","DOIUrl":"10.1016/j.radphyschem.2024.112281","url":null,"abstract":"<div><div>This paper aims to study the radiation shielding properties of lanthanide glasses, according to the formula <em>x</em>TiO<sub>2</sub>-51La<sub>2</sub>O<sub>3</sub>-(24-<em>x</em>) B<sub>2</sub>O<sub>3</sub>–8Gd<sub>2</sub>O<sub>3</sub>-8Nb<sub>2</sub>O<sub>5</sub>-6ZrO<sub>2</sub>-3SiO<sub>2</sub> (<em>x</em>= 0, 4, 8, 12, 16, <em>wt.</em>%). Using FLUKA Monte Carlo code, the mass attenuation coefficients (MAC), half-value layers (HVL), and effective atomic numbers (Z<sub><em>eff</em></sub>) of the lanthanide glasses were estimated at medical diagnostic energies (between 20 and 150 keV). The MACs of the glasses are between 0.5183 and 24.407 cm<sup>2</sup>/g for 0Ti, 0.5215-24.788 cm<sup>2</sup>/g for 4Ti, 0.5193-25.161 cm<sup>2</sup>/g for 8Ti, 0.5163-25.529 cm<sup>2</sup>/g for 12Ti, and 0.5183-25.916 cm<sup>2</sup>/g for 16Ti. These results are consistent with the Phy-X theoretical database (with a percentage difference below 3 %). The lanthanide glasses showed good photon shielding ability compared to lead concrete, and RS-360 & RS-253-G18 commercial glasses, commonly used shielding materials. In this work, 16Ti possesses the highest, lowest, and highest values of MAC, HVL, and Z<sub>eff</sub>, respectively, at the various energies investigated, which implies that the 16Ti sample has better shielding performance. All in all, this work demonstrated that adding TiO<sub>2</sub> to the glass samples could provide preferable shielding features.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"226 ","pages":"Article 112281"},"PeriodicalIF":2.8,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.radphyschem.2024.112278
Ebrahim Ebrahimi, Hamed Attariani
Swift Heavy Ions (SHI) irradiation, characterized by high kinetic energy ions, induces significant material/structural modification, e.g., latent track. However, the intricate interaction among various physics, i.e., mechanical stress, phase transition, and heat transfer, has been ignored in the continuum-based approaches in favor of simplicity. Here, we developed a two-dimensional coupled phase-field inelastic-thermal spike (PF-iTS) model to investigate the effect of thermal cross-talk, elastic energy, and irradiation fluence on latent track formation and size. The results reveal a shift in the critical electronic stopping energy and a reduced track radius under mechanical stress. Additionally, the study demonstrates the impact of thermal cross-talk between incidents, i.e., simultaneous and delayed double ion impacts, showing potential track merging and variations in track morphology.
{"title":"Effect of stress and irradiation fluence on latent track formation in swift heavy ion irradiation: A case study on TiO2","authors":"Ebrahim Ebrahimi, Hamed Attariani","doi":"10.1016/j.radphyschem.2024.112278","DOIUrl":"10.1016/j.radphyschem.2024.112278","url":null,"abstract":"<div><div>Swift Heavy Ions (SHI) irradiation, characterized by high kinetic energy ions, induces significant material/structural modification, e.g., latent track. However, the intricate interaction among various physics, i.e., mechanical stress, phase transition, and heat transfer, has been ignored in the continuum-based approaches in favor of simplicity. Here, we developed a two-dimensional coupled phase-field inelastic-thermal spike (PF-iTS) model to investigate the effect of thermal cross-talk, elastic energy, and irradiation fluence on latent track formation and size. The results reveal a shift in the critical electronic stopping energy and a reduced track radius under mechanical stress. Additionally, the study demonstrates the impact of thermal cross-talk between incidents, i.e., simultaneous and delayed double ion impacts, showing potential track merging and variations in track morphology.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"226 ","pages":"Article 112278"},"PeriodicalIF":2.8,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.radphyschem.2024.112271
M.I. Sayyed , M. Rashad , M. Elsafi , Yasser Maghrbi
The current work aims to develop a new lead calcium barium borate glasses doped with CuO (10PbO–20BaO–10CaO-(60-x)B2O3-xCuO, (x = 0, 5, 10, and 15 mol%)) and to experimentally report the radiation shielding properties of the developed glasses. The linear attenuation coefficient (LAC) was determined in two methods and we compared the results of both methods to check the accuracy in the experimental method. The effect of CuO on the LAC was examined and the results showed a positive relation between the amount of CuO and the LAC values and this is clearly seen at low energy range. The half and tenth thickness layers (HTL and TTL) were determined and the results showed that the HTL values equal to 0.051, 0.049, 0.047 and 0.045 cm at 60 keV, while they were 0.170, 0.163, 0.156 and 0.149 cm for TTL for the glasses with 0, 5, 10 and 15 mol% CuO respectively. The transmission efficiency (TF) results demonstrated that the addition of CuO to the glasses causes a reduction in the number of photons that can penetrate the glasses. The shielding efficiency parameter also confirms that the addition of CuO causes an enhancement in the radiation shielding properties for the prepared glasses.
{"title":"The impact of CuO in modifying the radiation shielding performance of PbO–BaO–CaO–B2O3–CuO: An experimental approach","authors":"M.I. Sayyed , M. Rashad , M. Elsafi , Yasser Maghrbi","doi":"10.1016/j.radphyschem.2024.112271","DOIUrl":"10.1016/j.radphyschem.2024.112271","url":null,"abstract":"<div><div>The current work aims to develop a new lead calcium barium borate glasses doped with CuO (10PbO–20BaO–10CaO-(60-x)B<sub>2</sub>O<sub>3</sub>-xCuO, (x = 0, 5, 10, and 15 mol%)) and to experimentally report the radiation shielding properties of the developed glasses. The linear attenuation coefficient (LAC) was determined in two methods and we compared the results of both methods to check the accuracy in the experimental method. The effect of CuO on the LAC was examined and the results showed a positive relation between the amount of CuO and the LAC values and this is clearly seen at low energy range. The half and tenth thickness layers (HTL and TTL) were determined and the results showed that the HTL values equal to 0.051, 0.049, 0.047 and 0.045 cm at 60 keV, while they were 0.170, 0.163, 0.156 and 0.149 cm for TTL for the glasses with 0, 5, 10 and 15 mol% CuO respectively. The transmission efficiency (TF) results demonstrated that the addition of CuO to the glasses causes a reduction in the number of photons that can penetrate the glasses. The shielding efficiency parameter also confirms that the addition of CuO causes an enhancement in the radiation shielding properties for the prepared glasses.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"226 ","pages":"Article 112271"},"PeriodicalIF":2.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-30DOI: 10.1016/j.radphyschem.2024.112276
J. Burguete , M. García-Cardosa , E. Antolín , B. Aguilar , J.D. Azcona
Accurately predicting dose delivery is crucial for achieving fully personalized treatments in external beam radiation therapy. However, this task remains challenging in some current technologies. In the case of Proton Therapy, for example, current systems employ complex strategies where a pencil beam is scanned in the tumor for treatment delivery. Some parameters in these treatments fluctuate and cannot be fully controlled. Therefore, a stochastic model that accounts for temporal uncertainties can be the best approach to describe these behaviors, particularly when the time-dependent beam interacts with other processes such as moving tumors or organs at risk.
This paper aims to provide medical physicists with a tool for accurately predicting the temporal structure of beam delivery. To achieve this, we followed a two-step process. First, we characterized the probability distributions for all relevant times in dose delivery. Second, we developed a model based on the measured data. This model serves as a starting point to improve treatment planning performance by providing a range of expected times for dose delivery. While the process was carried out using a compact synchrotron at our university, it can be easily adapted to other technologies.
{"title":"Stochastic model for predicting the temporal structure of the plan delivery in a synchrotron-based pencil beam scanning proton therapy system","authors":"J. Burguete , M. García-Cardosa , E. Antolín , B. Aguilar , J.D. Azcona","doi":"10.1016/j.radphyschem.2024.112276","DOIUrl":"10.1016/j.radphyschem.2024.112276","url":null,"abstract":"<div><div>Accurately predicting dose delivery is crucial for achieving fully personalized treatments in external beam radiation therapy. However, this task remains challenging in some current technologies. In the case of Proton Therapy, for example, current systems employ complex strategies where a pencil beam is scanned in the tumor for treatment delivery. Some parameters in these treatments fluctuate and cannot be fully controlled. Therefore, a stochastic model that accounts for temporal uncertainties can be the best approach to describe these behaviors, particularly when the time-dependent beam interacts with other processes such as moving tumors or organs at risk.</div><div>This paper aims to provide medical physicists with a tool for accurately predicting the temporal structure of beam delivery. To achieve this, we followed a two-step process. First, we characterized the probability distributions for all relevant times in dose delivery. Second, we developed a model based on the measured data. This model serves as a starting point to improve treatment planning performance by providing a range of expected times for dose delivery. While the process was carried out using a compact synchrotron at our university, it can be easily adapted to other technologies.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"226 ","pages":"Article 112276"},"PeriodicalIF":2.8,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-30DOI: 10.1016/j.radphyschem.2024.112272
Mayeen Uddin Khandaker , Hiromitsu Haba , Ahmed Rufai Usman , Mustafa Mahmoud , Naohiko Otuka , Samer K.I. Ali
In the present work, the excitation functions for the proton-induced nuclear reactions on natural zinc were measured in the energy range of 4–30 MeV using the well-established stacked-foil activation procedure. The activation products were measured based on their characteristic gamma lines using HPGe γ-ray spectrometry. The radioactivities determined were used for the calculation of cross-sections of the radionuclides of interest, i.e., 61Cu, 62,65,69mZn, 57Co and 66,67,68Ga. The cross-sections have also been compared with the available literature data and the theoretical prediction of the TALYS code via its latest TENDL-2023 library as well as the prediction of EMPIRE-3.2.2 model code. The results show a reasonable agreement when compared with the available literature data. This work, however, shows that the theoretical data extracted from the TENDL-2023 library and EMPIRE-3.2.2 default calculation significantly underestimate the experimental cross-sections of 57Co nuclide while they overestimate those of 69mZn. The present result has potential applications to improve the predicting capability of the model codes as well as to serve as additional data for the nuclear reaction cross-section database.
{"title":"Activation cross-sections of proton-induced nuclear reactions on natural zinc in the energy range of 4–30 MeV","authors":"Mayeen Uddin Khandaker , Hiromitsu Haba , Ahmed Rufai Usman , Mustafa Mahmoud , Naohiko Otuka , Samer K.I. Ali","doi":"10.1016/j.radphyschem.2024.112272","DOIUrl":"10.1016/j.radphyschem.2024.112272","url":null,"abstract":"<div><div>In the present work, the excitation functions for the proton-induced nuclear reactions on natural zinc were measured in the energy range of 4–30 MeV using the well-established stacked-foil activation procedure. The activation products were measured based on their characteristic gamma lines using HPGe γ-ray spectrometry. The radioactivities determined were used for the calculation of cross-sections of the radionuclides of interest, i.e., <sup>61</sup>Cu, <sup>62,65,69m</sup>Zn, <sup>57</sup>Co and <sup>66,67,68</sup>Ga. The cross-sections have also been compared with the available literature data and the theoretical prediction of the TALYS code via its latest TENDL-2023 library as well as the prediction of EMPIRE-3.2.2 model code. The results show a reasonable agreement when compared with the available literature data. This work, however, shows that the theoretical data extracted from the TENDL-2023 library and EMPIRE-3.2.2 default calculation significantly underestimate the experimental cross-sections of <sup>57</sup>Co nuclide while they overestimate those of <sup>69m</sup>Zn. The present result has potential applications to improve the predicting capability of the model codes as well as to serve as additional data for the nuclear reaction cross-section database.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"226 ","pages":"Article 112272"},"PeriodicalIF":2.8,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-29DOI: 10.1016/j.radphyschem.2024.112263
G.G.A. de Souza , H.N. da Luz , M. Bregant
In this work a set of simulations that aim at the optimization of Micropattern Gaseous Detectors (MPGD) for applications in X-ray fluorescence imaging in the energy range of 3 – 30 keV is presented. By studying the statistical distribution of electrons from interactions of X-rays with gases, the energy resolution limits after charge multiplication for 6 keV X-ray photons in Ar/CO(70/30) and Kr/CO(90/10) were calculated, resulting in energy resolutions of 15.4(4)% and 14.6(2)% respectively. These two mixtures were studied in simulations to evaluate the advantages of using krypton-based mixtures to reduce the presence of escape peaks in fluorescence spectra. A model to evaluate the X-ray fluorescence from the conductive materials inside the detectors was implemented, serving as a tool to estimate the extent of contamination of fluorescence spectra when using copper or aluminum layers in the material composition of MPGDs.
在这项工作中，介绍了一系列旨在优化微图案气体探测器（MPGD）的模拟，以应用于能量范围为 3-30 千伏的 X 射线荧光成像。通过研究 X 射线与气体相互作用产生的电子的统计分布，计算了 Ar/CO2(70/30)和 Kr/CO2(90/10)中 6 keV X 射线光子电荷倍增后的能量分辨率极限，结果是能量分辨率分别为 15.4(4)% 和 14.6(2)%。对这两种混合物进行了模拟研究，以评估使用氪基混合物减少荧光光谱中逸出峰的优势。还建立了一个模型来评估探测器内部导电材料产生的 X 射线荧光，该模型可作为一种工具，用于估算在 MPGD 的材料成分中使用铜层或铝层时荧光光谱的污染程度。
{"title":"Optimization of GEM detectors for applications in X-ray fluorescence imaging","authors":"G.G.A. de Souza , H.N. da Luz , M. Bregant","doi":"10.1016/j.radphyschem.2024.112263","DOIUrl":"10.1016/j.radphyschem.2024.112263","url":null,"abstract":"<div><div>In this work a set of simulations that aim at the optimization of Micropattern Gaseous Detectors (MPGD) for applications in X-ray fluorescence imaging in the energy range of 3<!--> <!-->–<!--> <!-->30<!--> <!-->keV is presented. By studying the statistical distribution of electrons from interactions of X-rays with gases, the energy resolution limits after charge multiplication for 6<!--> <!-->keV X-ray photons in Ar/CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>(70/30) and Kr/CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>(90/10) were calculated, resulting in energy resolutions of 15.4(4)% and 14.6(2)% respectively. These two mixtures were studied in simulations to evaluate the advantages of using krypton-based mixtures to reduce the presence of escape peaks in fluorescence spectra. A model to evaluate the X-ray fluorescence from the conductive materials inside the detectors was implemented, serving as a tool to estimate the extent of contamination of fluorescence spectra when using copper or aluminum layers in the material composition of MPGDs.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"226 ","pages":"Article 112263"},"PeriodicalIF":2.8,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-28DOI: 10.1016/j.radphyschem.2024.112267
Asaad H. Ismail , Hoshanc S. Rashid , Ahmed Abduljabbar Omar , Ali H. Alomari , Saeed M. Al-Qahtani , Talal A. Alnaemi , Nataša Todorović , Serpil Aközcan Pehlivanoglu , Michele Guida , Simona Mancini
The research aimed to study the safety of the dose-staged Gamma Knife radiosurgery (GKRS) on the patients' organs, by evaluating the equivalent and effective doses delivered to various body parts and examining the impacts on the blood parameters. The case study consisted of 30 patients with different brain lesions undergone to GKRS. To assess the radiation exposure on the different body parts, gamma dose rates were measured using a survey radiation dosimeter. The results demonstrated that the GKRS beam effectively backscatters on the patient's body, considering the irradiation doses and the exposure time. Body parts in closer proximity to the target (radiation beam) received higher gamma doses compared to other areas. High and low values of gamma dose rate were measured in the two configurations: high irradiation dose (80 Gy for 46.47 min) and low irradiation dose (10 Gy per 15.7 min) for the brain lesions of Trigeminal Neuralgia and Meningioma, respectively. Radiobiological effects were estimated following the international guidelines revealing significant radiation impacts on some organs. Hematological effects were also evaluated with variations depending on the radiation exposure dose and the exposure time. Some blood cells showed radiation-related impacts. Notably, the high dose of 80 Gy administered over 46.47 min of exposure for trigeminal brain lesions had a greater influence on the blood parameters compared to the low dose of 10 Gy over 15.7 min of exposure for acoustic neuroma brain lesions. Consequently, it turned out that increases in gamma-ray doses resulted in significant impacts on specific blood parameters.
{"title":"Radiobiological evaluation of the impact of the treatment with the gamma knife radiosurgery technique on the body parts of patients with different brain lesions: Does the radiation exposure affect also the Patient's blood components?","authors":"Asaad H. Ismail , Hoshanc S. Rashid , Ahmed Abduljabbar Omar , Ali H. Alomari , Saeed M. Al-Qahtani , Talal A. Alnaemi , Nataša Todorović , Serpil Aközcan Pehlivanoglu , Michele Guida , Simona Mancini","doi":"10.1016/j.radphyschem.2024.112267","DOIUrl":"10.1016/j.radphyschem.2024.112267","url":null,"abstract":"<div><div>The research aimed to study the safety of the dose-staged Gamma Knife radiosurgery (GKRS) on the patients' organs, by evaluating the equivalent and effective doses delivered to various body parts and examining the impacts on the blood parameters. The case study consisted of 30 patients with different brain lesions undergone to GKRS. To assess the radiation exposure on the different body parts, gamma dose rates were measured using a survey radiation dosimeter. The results demonstrated that the GKRS beam effectively backscatters on the patient's body, considering the irradiation doses and the exposure time. Body parts in closer proximity to the target (radiation beam) received higher gamma doses compared to other areas. High and low values of gamma dose rate were measured in the two configurations: high irradiation dose (80 Gy for 46.47 min) and low irradiation dose (10 Gy per 15.7 min) for the brain lesions of Trigeminal Neuralgia and Meningioma, respectively. Radiobiological effects were estimated following the international guidelines revealing significant radiation impacts on some organs. Hematological effects were also evaluated with variations depending on the radiation exposure dose and the exposure time. Some blood cells showed radiation-related impacts. Notably, the high dose of 80 Gy administered over 46.47 min of exposure for trigeminal brain lesions had a greater influence on the blood parameters compared to the low dose of 10 Gy over 15.7 min of exposure for acoustic neuroma brain lesions. Consequently, it turned out that increases in gamma-ray doses resulted in significant impacts on specific blood parameters.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"226 ","pages":"Article 112267"},"PeriodicalIF":2.8,"publicationDate":"2024-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142330108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study estimated the size-specific dose estimates (SSDE) in different scan phases and inter-phase variations of multi-phase abdomen-pelvis CT examinations. Various methods employed for determination of SSDE, which takes into account the size of the patient, were compared for 51 multiphase abdomen-pelvis CT examinations using custom written software. These methods are based on effective diameter, water equivalent diameter derived from region of interest and segmentation techniques, diameter of central image and whole scan series. Significant variation was observed in SSDE of pre-contrast phase in comparison to other phases. The effective dose was also estimated and correlated with SSDE. The results indicate that the underestimation in the dose estimated using the machine parameter, CTDIvol, was in the range of 10%–60% when compared with SSDE. This study concludes that the average SSDE of the whole examination is a better representation of patient dose in the case of multi-phase examinations. It highlights the need for integration of SSDE calculating software in the CT scanner systems for accurate estimation of patient doses.
{"title":"Size specific dose estimates and effective dose in multiphase abdomen-pelvis CT examinations","authors":"Philomina Akhilesh , M.S. Pathan , S.D. Sharma , B.K. Sapra","doi":"10.1016/j.radphyschem.2024.112269","DOIUrl":"10.1016/j.radphyschem.2024.112269","url":null,"abstract":"<div><div>This study estimated the size-specific dose estimates (SSDE) in different scan phases and inter-phase variations of multi-phase abdomen-pelvis CT examinations. Various methods employed for determination of SSDE, which takes into account the size of the patient, were compared for 51 multiphase abdomen-pelvis CT examinations using custom written software. These methods are based on effective diameter, water equivalent diameter derived from region of interest and segmentation techniques, diameter of central image and whole scan series. Significant variation was observed in SSDE of pre-contrast phase in comparison to other phases. The effective dose was also estimated and correlated with SSDE. The results indicate that the underestimation in the dose estimated using the machine parameter, CTDI<sub>vol</sub>, was in the range of 10%–60% when compared with SSDE. This study concludes that the average SSDE of the whole examination is a better representation of patient dose in the case of multi-phase examinations. It highlights the need for integration of SSDE calculating software in the CT scanner systems for accurate estimation of patient doses.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"226 ","pages":"Article 112269"},"PeriodicalIF":2.8,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1016/j.radphyschem.2024.112248
Yanfeng Xie , Soo Hyun Byun
We present a novel beta spectrometer that consists of two identical plastic scintillators with one scintillator screened by a thin copper plate as a beta shield. The screened scintillator responds only to gamma photons while the other scintillator responds to both beta particles and gamma photons. The spectrometer’s response to beta and gamma radiations was characterized by experiments and Monte Carlo simulations. The gamma responses of the scintillators were in good agreement in most energy region while the screened scintillator showed a notable gamma attenuation in the low energy region below 150 keV. Comparison of the simulated and measured pulse height spectra showed good agreements for both beta and gamma radiations. For beta spectrum analysis, a simple gamma subtraction method and a convolutional neural network (CNN)-based method were investigated for various mixed beta–gamma fields. The subtraction method showed good accuracy in most energy regions while a notable overestimation of beta fluence was observed in the low energy region, which was caused by the gamma attenuation effect of the screened scintillator. The outcomes of the CNN method showed good agreements with the true beta fluence spectra for the validation dataset, however, the CNN model led to a significant overestimation for a dataset produced using the radionuclides that have not been used in the training datasets. To take the advantages of the outperforming features of both unfolding methods, a hybrid algorithm was deduced by applying a tolerance range to the subtraction result.
{"title":"Enhancement of beta spectrometry using double scintillators and ML-based unfolding","authors":"Yanfeng Xie , Soo Hyun Byun","doi":"10.1016/j.radphyschem.2024.112248","DOIUrl":"10.1016/j.radphyschem.2024.112248","url":null,"abstract":"<div><div>We present a novel beta spectrometer that consists of two identical plastic scintillators with one scintillator screened by a thin copper plate as a beta shield. The screened scintillator responds only to gamma photons while the other scintillator responds to both beta particles and gamma photons. The spectrometer’s response to beta and gamma radiations was characterized by experiments and Monte Carlo simulations. The gamma responses of the scintillators were in good agreement in most energy region while the screened scintillator showed a notable gamma attenuation in the low energy region below 150 keV. Comparison of the simulated and measured pulse height spectra showed good agreements for both beta and gamma radiations. For beta spectrum analysis, a simple gamma subtraction method and a convolutional neural network (CNN)-based method were investigated for various mixed beta–gamma fields. The subtraction method showed good accuracy in most energy regions while a notable overestimation of beta fluence was observed in the low energy region, which was caused by the gamma attenuation effect of the screened scintillator. The outcomes of the CNN method showed good agreements with the true beta fluence spectra for the validation dataset, however, the CNN model led to a significant overestimation for a dataset produced using the radionuclides that have not been used in the training datasets. To take the advantages of the outperforming features of both unfolding methods, a hybrid algorithm was deduced by applying a tolerance range to the subtraction result.</div></div>","PeriodicalId":20861,"journal":{"name":"Radiation Physics and Chemistry","volume":"226 ","pages":"Article 112248"},"PeriodicalIF":2.8,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142418012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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