Pub Date : 2024-12-16DOI: 10.1016/j.apradiso.2024.111642
Andrew C. Candia , Georg Bollen , Suvan Campbell , Ana Henriques , Alain Lapierre , Samuel Nash , Stefan Schwarz , Chandana Sumithrarachchi , Antonio C.C. Villari , Katharina A. Domnanich
For the generation of beams with the offline ion source at the Facility for Rare Isotope Beams (FRIB), suitable source samples are required. Arsenic-73 is a frequently requested user beam due to its significance in nuclear structure studies and astrophysics. In this work, we outline the process of preparing a 73As source sample, containing (5.76 ± 0.37)∗1014 atoms of 73As, which was successfully used to generate a 73As beam for a multi-day user experiment. Silver arsenate was chosen as the chemical form, due to its favorable volatility within the designated operating temperature range. We refined the precipitation method using stable arsenic prior to its application with the 73As sample, resulting in precipitation yields of (99.4 ± 4.5)%.
{"title":"Preparation of a 73As source sample for application in an offline ion source","authors":"Andrew C. Candia , Georg Bollen , Suvan Campbell , Ana Henriques , Alain Lapierre , Samuel Nash , Stefan Schwarz , Chandana Sumithrarachchi , Antonio C.C. Villari , Katharina A. Domnanich","doi":"10.1016/j.apradiso.2024.111642","DOIUrl":"10.1016/j.apradiso.2024.111642","url":null,"abstract":"<div><div>For the generation of beams with the offline ion source at the Facility for Rare Isotope Beams (FRIB), suitable source samples are required. Arsenic-73 is a frequently requested user beam due to its significance in nuclear structure studies and astrophysics. In this work, we outline the process of preparing a <sup>73</sup>As source sample, containing (5.76 ± 0.37)∗10<sup>14</sup> atoms of <sup>73</sup>As, which was successfully used to generate a <sup>73</sup>As beam for a multi-day user experiment. Silver arsenate was chosen as the chemical form, due to its favorable volatility within the designated operating temperature range. We refined the precipitation method using stable arsenic prior to its application with the <sup>73</sup>As sample, resulting in precipitation yields of (99.4 ± 4.5)%.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111642"},"PeriodicalIF":1.6,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142891553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-16DOI: 10.1016/j.apradiso.2024.111643
Yue Li , Yongqiang Zhang , Guoqiang Zhong , Wenjing Pu , Wei Lu , Weihua Wang
Liquid scintillator consists of an organic solvent and one or more scintillation solutes, which can emit light pulses after absorbing X- and γ-rays, or high-energy particles. It has the characteristics of strong neutron/γ-ray (n/γ) discrimination, short decay time, unlimited size and low cost, which plays an important role in high-sensitivity and large-scale radiation detection, especially in the construction and safe operation of nuclear facilities. However, the impact of solvent selection and moisture content on the fluorescence-scintillation properties of scintillators has not been adequately investigated in the literature. In this study, liquid scintillators consisting of scintillation solutes, 2, 5-diphenyl-oxazole and 1, 4-bis (5-phenyl-2-oxazolyl) benzene, were prepared with different moisture contents, which were determined using the Karl-Fischer method. The fluorescence emission spectra, scintillation sensitivity and n/γ discrimination were systematically characterized using various solvents with corresponding moisture contents. The results show that the scintillation count rate and n/γ discrimination reach their maximum values when employing p-xylene as the solvent and maintaining moisture content below 20 ppm. The theoretical calculation elucidates the performance degradation of liquid scintillators induced by moisture.
{"title":"Solvents with different moisture levels: Critical impact factors on fluorescence-scintillation properties of liquid scintillators","authors":"Yue Li , Yongqiang Zhang , Guoqiang Zhong , Wenjing Pu , Wei Lu , Weihua Wang","doi":"10.1016/j.apradiso.2024.111643","DOIUrl":"10.1016/j.apradiso.2024.111643","url":null,"abstract":"<div><div>Liquid scintillator consists of an organic solvent and one or more scintillation solutes, which can emit light pulses after absorbing X- and γ-rays, or high-energy particles. It has the characteristics of strong neutron/γ-ray (n/γ) discrimination, short decay time, unlimited size and low cost, which plays an important role in high-sensitivity and large-scale radiation detection, especially in the construction and safe operation of nuclear facilities. However, the impact of solvent selection and moisture content on the fluorescence-scintillation properties of scintillators has not been adequately investigated in the literature. In this study, liquid scintillators consisting of scintillation solutes, 2, 5-diphenyl-oxazole and 1, 4-bis (5-phenyl-2-oxazolyl) benzene, were prepared with different moisture contents, which were determined using the Karl-Fischer method. The fluorescence emission spectra, scintillation sensitivity and n/γ discrimination were systematically characterized using various solvents with corresponding moisture contents. The results show that the scintillation count rate and n/γ discrimination reach their maximum values when employing <em>p</em>-xylene as the solvent and maintaining moisture content below 20 ppm. The theoretical calculation elucidates the performance degradation of liquid scintillators induced by moisture.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111643"},"PeriodicalIF":1.6,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142871085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-15DOI: 10.1016/j.apradiso.2024.111632
Yiyuan Wu , Bowen Cai , Jijun Zou , Yiwei Yang , Jinhai Li , Jiangfeng Wan , Xincun Peng , Yu Liu , Dexin Xiao , Bin Tang
The white neutron source driven by an electron accelerator utilizes a pulsed electron beam to bombard a target, producing neutrons through photoneutron reactions. The white neutron source of photoneutron reaction has advantages such as compact structure, low cost, capability of generating ultra-short pulse, and wide applications in the resonance energy region, effectively complementing reactor neutron sources and spallation neutron sources. The development of high-current, high-power electron accelerator-driven white neutron sources is of significant importance for neutron science research and nuclear technology applications. However, constructing such a strong-current, high-power electron accelerator-driven white neutron source is complex, and a lot of theoretical simulation work is needed in the early stage to guide the obtaining of a set of optimal source parameters, as well as thermal analysis of the electron bombardment to address target cooling issues. Therefore, in this paper, Monte Carlo algorithm is used to comprehensively simulate and optimize the target station of 35 MeV/ 2 mA@ 70 kW electron accelerator driven white neutron source. Including the structural design of the target, the study of neutron physics parameters, distribution of electron energy deposition, and distribution of radiation damage caused by electrons. In addition, thermal analysis of the target is conducted using the finite element analysis software ANSYS. The research results of this paper will provide important references and bases for guiding the engineering design of high-power electron accelerator-driven white neutron source target stations.
{"title":"Simulation analysis of 35 MeV high-power electron accelerator driven white neutron source target","authors":"Yiyuan Wu , Bowen Cai , Jijun Zou , Yiwei Yang , Jinhai Li , Jiangfeng Wan , Xincun Peng , Yu Liu , Dexin Xiao , Bin Tang","doi":"10.1016/j.apradiso.2024.111632","DOIUrl":"10.1016/j.apradiso.2024.111632","url":null,"abstract":"<div><div>The white neutron source driven by an electron accelerator utilizes a pulsed electron beam to bombard a target, producing neutrons through photoneutron reactions. The white neutron source of photoneutron reaction has advantages such as compact structure, low cost, capability of generating ultra-short pulse, and wide applications in the resonance energy region, effectively complementing reactor neutron sources and spallation neutron sources. The development of high-current, high-power electron accelerator-driven white neutron sources is of significant importance for neutron science research and nuclear technology applications. However, constructing such a strong-current, high-power electron accelerator-driven white neutron source is complex, and a lot of theoretical simulation work is needed in the early stage to guide the obtaining of a set of optimal source parameters, as well as thermal analysis of the electron bombardment to address target cooling issues. Therefore, in this paper, Monte Carlo algorithm is used to comprehensively simulate and optimize the target station of 35 MeV/ 2 mA@ 70 kW electron accelerator driven white neutron source. Including the structural design of the target, the study of neutron physics parameters, distribution of electron energy deposition, and distribution of radiation damage caused by electrons. In addition, thermal analysis of the target is conducted using the finite element analysis software ANSYS. The research results of this paper will provide important references and bases for guiding the engineering design of high-power electron accelerator-driven white neutron source target stations.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111632"},"PeriodicalIF":1.6,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142871082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-15DOI: 10.1016/j.apradiso.2024.111641
İ. Erkoyuncu , İ. Demirkol , F. Akman , M.R. Kaçal , H. Polat , K. Dilsiz
In this study, the gamma radiation shielding properties of concrete samples reinforced with 10%, 20%, 30%, 40% and 50% of the cement weight of brass alloy were investigated. To test gamma shielding performance of the samples, mass and linear attenuation coefficients, half and tenth value layers, effective atomic number and radiation protection efficiency parameters were determined experimentally, theoretically and Monte Carlo simulations (GEANT4 and FLUKA). The studies were performed at 11 different gamma energies that range from 59.5 to 1332.5 keV emitted from 22Na, 60Co, 133Ba, 137Cs and 241Am radioactive sources. The obtained results showed that the gamma shielding property of the samples increases with increasing brass alloy amount, and the sample reinforced with 50% brass alloy was the most effective one to shield gamma radiation. Neutron shielding properties of the sample reinforced with 50% brass alloy were therefore investigated by adding 5%, 10%, 15% and 20% boron carbide (B4C). The neutron permeability, which is an important parameter in terms of the neutron shielding performance of B4C added concrete samples, was investigated by using GEANT4 and FLUKA simulation programs. While the total macroscopic cross section results obtained with GEANT4 for concretes coded as P0, P50, P50B5, P50B10, P50B15 and P50B20 are 2.0290, 2.0324, 2.0343, 2.0346, 2.0361 and 2.0367 cm-1, respectively, the results obtained with FLUKA are 2.0287, 2.0322, 2.0337, 2.0342, 2.0357 and 2.0362 cm-1, respectively. Therefore, the sample containing 20% B4C is the sample that best shields neutron radiation. In addition to the radiation shielding properties of the produced samples, the mechanical properties such as compressive strength, Schmidt surface hardness, ultrasound pulse velocity were also tested in terms of usability.
{"title":"A study on the mechanical and radiation shielding characteristics of concrete samples reinforced with brass alloy and boron carbide","authors":"İ. Erkoyuncu , İ. Demirkol , F. Akman , M.R. Kaçal , H. Polat , K. Dilsiz","doi":"10.1016/j.apradiso.2024.111641","DOIUrl":"10.1016/j.apradiso.2024.111641","url":null,"abstract":"<div><div>In this study, the gamma radiation shielding properties of concrete samples reinforced with 10%, 20%, 30%, 40% and 50% of the cement weight of brass alloy were investigated. To test gamma shielding performance of the samples, mass and linear attenuation coefficients, half and tenth value layers, effective atomic number and radiation protection efficiency parameters were determined experimentally, theoretically and Monte Carlo simulations (GEANT4 and FLUKA). The studies were performed at 11 different gamma energies that range from 59.5 to 1332.5 keV emitted from <sup>22</sup>Na, <sup>60</sup>Co, <sup>133</sup>Ba, <sup>137</sup>Cs and <sup>241</sup>Am radioactive sources. The obtained results showed that the gamma shielding property of the samples increases with increasing brass alloy amount, and the sample reinforced with 50% brass alloy was the most effective one to shield gamma radiation. Neutron shielding properties of the sample reinforced with 50% brass alloy were therefore investigated by adding 5%, 10%, 15% and 20% boron carbide (B<sub>4</sub>C). The neutron permeability, which is an important parameter in terms of the neutron shielding performance of B<sub>4</sub>C added concrete samples, was investigated by using GEANT4 and FLUKA simulation programs. While the total macroscopic cross section results obtained with GEANT4 for concretes coded as P0, P50, P50B5, P50B10, P50B15 and P50B20 are 2.0290, 2.0324, 2.0343, 2.0346, 2.0361 and 2.0367 cm-1, respectively, the results obtained with FLUKA are 2.0287, 2.0322, 2.0337, 2.0342, 2.0357 and 2.0362 cm-1, respectively. Therefore, the sample containing 20% B<sub>4</sub>C is the sample that best shields neutron radiation. In addition to the radiation shielding properties of the produced samples, the mechanical properties such as compressive strength, Schmidt surface hardness, ultrasound pulse velocity were also tested in terms of usability.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111641"},"PeriodicalIF":1.6,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142871078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-15DOI: 10.1016/j.apradiso.2024.111639
C.E. Bracamonte-Estrada , R. Bernal , V.E. Álvarez-Montaño , A.I. Castro-Campoy , C. Cruz-Vázquez
This work reports the synthesis and beta particle excited thermoluminescence (TL) characteristics of NaF and NaF:Tm phosphors synthesized via wet precipitation. The samples were subjected to thermal annealing at 750 °C for 5, 10, and 24 h in an air atmosphere. A sensitization effect is observed in repeated irradiation-TL readout cycles. The sensitization effect significantly decreases with increasing duration of thermal treatments and with decreasing irradiation dose. Furthermore, doping with Tm simplifies the shape of the glow curves in the region of maximum thermoluminescent intensity, located between 200 and 250 °C, a temperature range considered suitable for thermoluminescent dosimetry. The integrated TL is a linear function of the irradiation dose for the tested dose range (0.05 Gy–1.78 Gy). NaF is presented as a promising alternative to LiF for developing highly sensitive TL dosimeters, and it is concluded that NaF is a promising phosphor material, warranting further research into its dosimetric capabilities.
{"title":"Thermoluminescence of NaF and NaF:Tm phosphors exposed to beta particle irradiation","authors":"C.E. Bracamonte-Estrada , R. Bernal , V.E. Álvarez-Montaño , A.I. Castro-Campoy , C. Cruz-Vázquez","doi":"10.1016/j.apradiso.2024.111639","DOIUrl":"10.1016/j.apradiso.2024.111639","url":null,"abstract":"<div><div>This work reports the synthesis and beta particle excited thermoluminescence (TL) characteristics of NaF and NaF:Tm phosphors synthesized via wet precipitation. The samples were subjected to thermal annealing at 750 °C for 5, 10, and 24 h in an air atmosphere. A sensitization effect is observed in repeated irradiation-TL readout cycles. The sensitization effect significantly decreases with increasing duration of thermal treatments and with decreasing irradiation dose. Furthermore, doping with Tm simplifies the shape of the glow curves in the region of maximum thermoluminescent intensity, located between 200 and 250 °C, a temperature range considered suitable for thermoluminescent dosimetry. The integrated TL is a linear function of the irradiation dose for the tested dose range (0.05 Gy–1.78 Gy). NaF is presented as a promising alternative to LiF for developing highly sensitive TL dosimeters, and it is concluded that NaF is a promising phosphor material, warranting further research into its dosimetric capabilities.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111639"},"PeriodicalIF":1.6,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142871087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-15DOI: 10.1016/j.apradiso.2024.111637
Qiuying Liang , Yaling Zhang , Wei Wang , Yongwei Yang , Lei Yang
225Ac radionuclides have shown great potential for use as radiopharmaceuticals in cancer therapy by conjugation them with carrier molecules due to their strong cytotoxicity, suitable half-life, and ability to be used as 213Bi generators. The production of 225Ac via bombardment of 232Th targets with accelerated protons is currently the most widely used method in the world. In order to better quantify the achievable yields and radiopurity, this production process is simulated in this study. Firstly, the formation cross sections of 225Ac、226Ac、227Ac、225Th、229Pa、225Ra、229Th, and 227 Ra by proton incident on thorium with energies up to 500 MeV is calculated using Monte Carlo transport codes PHITS in combination with different spallation reaction models(INCL4.6 + GEM, Bertini + GEM, JAM + GEM), and are compared them with the available experimental data as well as the nuclear data given by TENDL-2021. Then, based on the predicted and experimental cross sections, the production yields and purity of 225Ac and other co-produced medical isotopes during and after irradiation are investigated.
{"title":"Study of medical radioisotope production of Ac-225 by proton accelerator","authors":"Qiuying Liang , Yaling Zhang , Wei Wang , Yongwei Yang , Lei Yang","doi":"10.1016/j.apradiso.2024.111637","DOIUrl":"10.1016/j.apradiso.2024.111637","url":null,"abstract":"<div><div><sup>225</sup>Ac radionuclides have shown great potential for use as radiopharmaceuticals in cancer therapy by conjugation them with carrier molecules due to their strong cytotoxicity, suitable half-life, and ability to be used as <sup>213</sup>Bi generators. The production of <sup>225</sup>Ac via bombardment of <sup>232</sup>Th targets with accelerated protons is currently the most widely used method in the world. In order to better quantify the achievable yields and radiopurity, this production process is simulated in this study. Firstly, the formation cross sections of <sup>225</sup>Ac、<sup>226</sup>Ac、<sup>227</sup>Ac、<sup>225</sup>Th、<sup>229</sup>Pa、<sup>225</sup>Ra、<sup>229</sup>Th, and <sup>227</sup> Ra by proton incident on thorium with energies up to 500 MeV is calculated using Monte Carlo transport codes PHITS in combination with different spallation reaction models(INCL4.6 + GEM, Bertini + GEM, JAM + GEM), and are compared them with the available experimental data as well as the nuclear data given by TENDL-2021. Then, based on the predicted and experimental cross sections, the production yields and purity of <sup>225</sup>Ac and other co-produced medical isotopes during and after irradiation are investigated.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111637"},"PeriodicalIF":1.6,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142891555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-15DOI: 10.1016/j.apradiso.2024.111640
Hasan Tuner , François Trompier , Alexander Romanyukha
This paper presents the results of the first intercomparison exercise on Electron Paramagnetic Resonance (EPR) dosimetry using sorbitol, where the performance parameters of sorbitol as dosimetric material were evaluated by three independent participants. Each participant was asked to determine a calibration curve using a set of sorbitol powder samples irradiated to four different doses (1.00, 2.50, 5.00, and 10.00 Gy of air kerma). The calibration doses were known to the participants, who were asked to measure each sample three times, and to report the EPR signal response, the mass of aliquots measured, and the parameters of EPR signal acquisition and signal evaluation. Critical dose and detection limit were calculated based on the calibration-curve parameters obtained by each participant. The mean values of the detection limit and average critical dose were found to be 802 ± 148 mGy and 411 ± 77 mGy, respectively. These values were compared with those of for alanine, glass and tooth enamel. The participants were also provided with four blind samples irradiated to four unknown doses, and their reported doses were compared with the delivered doses and performance quotient was calculated for each participant. The findings indicate that sorbitol is a promising candidate for accidental and retrospective dosimetry.
{"title":"Intercomparison exercise on electron paramagnetic resonance dosimetry in sorbitol","authors":"Hasan Tuner , François Trompier , Alexander Romanyukha","doi":"10.1016/j.apradiso.2024.111640","DOIUrl":"10.1016/j.apradiso.2024.111640","url":null,"abstract":"<div><div>This paper presents the results of the first intercomparison exercise on Electron Paramagnetic Resonance (EPR) dosimetry using sorbitol, where the performance parameters of sorbitol as dosimetric material were evaluated by three independent participants. Each participant was asked to determine a calibration curve using a set of sorbitol powder samples irradiated to four different doses (1.00, 2.50, 5.00, and 10.00 Gy of air kerma). The calibration doses were known to the participants, who were asked to measure each sample three times, and to report the EPR signal response, the mass of aliquots measured, and the parameters of EPR signal acquisition and signal evaluation. Critical dose and detection limit were calculated based on the calibration-curve parameters obtained by each participant. The mean values of the detection limit and average critical dose were found to be 802 ± 148 mGy and 411 ± 77 mGy, respectively. These values were compared with those of for alanine, glass and tooth enamel. The participants were also provided with four blind samples irradiated to four unknown doses, and their reported doses were compared with the delivered doses and performance quotient was calculated for each participant. The findings indicate that sorbitol is a promising candidate for accidental and retrospective dosimetry.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111640"},"PeriodicalIF":1.6,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142876048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-14DOI: 10.1016/j.apradiso.2024.111627
Arnaud Deschavannes , Marie Piquemal , Catherine Rioufol , Anthony Clotagatide
For hepatobiliary scintigraphy, the radiopharmaceutical drug, ETIFENIN (TECHIDA®), labelled with technetium-99m, is used as a substitute for MEBROFENIN (CHOLEDIAM®). It is generally accepted that radiopharmaceuticals should be checked prior to injection, in particular by determining radiochemical purity, to ensure high-quality images. Radiochromatographic techniques or methods described in the Summary of Product Characteristics (SmPC) and the European Pharmacopeia (Ph. Eur.) for quality control of [99mTc]Tc-ETIFENIN were considered impractical in routine nuclear medicine services (e.g. time-consuming and difficult to use). Following a literature review and screening phase, a quality control method was selected using a two-strip method. For detection and quantification of [99mTc]TcO4−, a glass microfiber paper impregnated with silica acid (ITLC-SA®) was used with a NaCl 20% mobile phase (w/v). For [99mTc]TcO2, glass microfiber paper impregnated with silica gel (ITLC-SG®) was used together with an absolute methanol mobile phase. The aim of this work was to validate this alternative analytical method. To do so, the recommendations of the European Association of Nuclear Medicine (EANM), adapted from the International Council of Harmonization Q2 (ICH Q2), were followed. Seven parameters were analyzed: specificity, linearity, precision, accuracy, robustness, limit of quantification and range. Additionally, migration time was also evaluated. This two-strip method appears to be specific (Rsmean > 2.0), linear (slope close to 1, R2 ≥ 0.99), precise (CV < 2.0%), accurate (%impuritiestwo-strip method > %impuritiesreference), robust (CV < 2.0%), with an acceptable LoQ (S/N > 10:1) and a wide range (1.6–540 MBq/mL). Time of analysis appears to be clearly integrable into routine clinical practices (< 20 min). The alternative two-strip method NaCl 20% - ITLC-SA® and Methanol - ITLC-SG® represents an efficient quality control procedure. It allows the identification and quantification of the ratios of labelled [99mTc]Tc-ETIFENIN together with two potential impurities consisting of [99mTc]TcO4− and [99mTc]TcO2.
{"title":"Validation of an alternative two-strip method for the quality control of [99mTc]Tc-ETIFENIN (TECHIDA®)","authors":"Arnaud Deschavannes , Marie Piquemal , Catherine Rioufol , Anthony Clotagatide","doi":"10.1016/j.apradiso.2024.111627","DOIUrl":"10.1016/j.apradiso.2024.111627","url":null,"abstract":"<div><div>For hepatobiliary scintigraphy, the radiopharmaceutical drug, ETIFENIN (TECHIDA®), labelled with technetium-99m, is used as a substitute for MEBROFENIN (CHOLEDIAM®). It is generally accepted that radiopharmaceuticals should be checked prior to injection, in particular by determining radiochemical purity, to ensure high-quality images. Radiochromatographic techniques or methods described in the Summary of Product Characteristics (SmPC) and the European Pharmacopeia (Ph. Eur.) for quality control of [<sup>99m</sup>Tc]Tc-ETIFENIN were considered impractical in routine nuclear medicine services (e.g. time-consuming and difficult to use). Following a literature review and screening phase, a quality control method was selected using a two-strip method. For detection and quantification of [<sup>99m</sup>Tc]TcO<sub>4</sub><sup>−</sup>, a glass microfiber paper impregnated with silica acid (ITLC-SA®) was used with a NaCl 20% mobile phase (w/v). For [<sup>99m</sup>Tc]TcO<sub>2</sub>, glass microfiber paper impregnated with silica gel (ITLC-SG®) was used together with an absolute methanol mobile phase. The aim of this work was to validate this alternative analytical method. To do so, the recommendations of the European Association of Nuclear Medicine (EANM), adapted from the International Council of Harmonization Q2 (ICH Q2), were followed. Seven parameters were analyzed: specificity, linearity, precision, accuracy, robustness, limit of quantification and range. Additionally, migration time was also evaluated. This two-strip method appears to be specific (Rs<sub>mean</sub> > 2.0), linear (slope close to 1, R<sup>2</sup> ≥ 0.99), precise (CV < 2.0%), accurate (%impurities<sub>two-strip method</sub> > %impurities<sub>reference</sub>), robust (CV < 2.0%), with an acceptable LoQ (S/N > 10:1) and a wide range (1.6–540 MBq/mL). Time of analysis appears to be clearly integrable into routine clinical practices (< 20 min). The alternative two-strip method NaCl 20% - ITLC-SA® and Methanol - ITLC-SG® represents an efficient quality control procedure. It allows the identification and quantification of the ratios of labelled [<sup>99m</sup>Tc]Tc-ETIFENIN together with two potential impurities consisting of [<sup>99m</sup>Tc]TcO<sub>4</sub><sup>−</sup> and [<sup>99m</sup>Tc]TcO<sub>2</sub>.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111627"},"PeriodicalIF":1.6,"publicationDate":"2024-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142982569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-13DOI: 10.1016/j.apradiso.2024.111636
Zeinab Fardi, Payvand Taherparvar
Uveal melanoma is the most common primary eye cancer with the highest incidence. BEBIG 106Ru/106Rh ophthalmic plaques more used for the treatment of these eye malignancies, mainly malignancies with small to medium sizes. In this study, we evaluate dose distributions around a voxelized eye phantom due to CCA and CCB eye plaque using GATE code. The phantom contains the important eye substructures with three defined tumors with the same basal diameter and different apical thicknesses of 3 mm, 4 mm, and 5 mm. The validation for source and plaques have been performed by comparing the obtained results for energy spectrum of the source and percentage depth-dose along the central axis of plaques with the available published data. The delivered doses to the eye components and tumors show that received doses by different eye substructures depend on the size of the plaque and tumor thickness. Results show that the knowledge of the height of tumor apex before treating eye tumors with ophthalmic plaques is essential. On the other hand, about 32% (62%) of the dose deposition belongs to secondary produced photons in the CCA (CCB) plaque. Moreover, comparing the results obtained from two plaques, showed that although the CCB plaque produces a more uniform dose distribution in the tumor, the CCA plaque presents a higher dose delivery to the tumor and a lower one to the critical structures for all three tumor sizes. Therefore, it is recommended to use CCA plaque for eye tumors up to 5 mm height of the apex.
{"title":"Monte Carlo investigation of dose distribution of two model 106Ru/106Rh ophthalmic plaques in a realistic human eye model with different uveal melanoma size","authors":"Zeinab Fardi, Payvand Taherparvar","doi":"10.1016/j.apradiso.2024.111636","DOIUrl":"10.1016/j.apradiso.2024.111636","url":null,"abstract":"<div><div>Uveal melanoma is the most common primary eye cancer with the highest incidence. BEBIG <sup>106</sup>Ru/<sup>106</sup>Rh ophthalmic plaques more used for the treatment of these eye malignancies, mainly malignancies with small to medium sizes. In this study, we evaluate dose distributions around a voxelized eye phantom due to CCA and CCB eye plaque using GATE code. The phantom contains the important eye substructures with three defined tumors with the same basal diameter and different apical thicknesses of 3 mm, 4 mm, and 5 mm. The validation for source and plaques have been performed by comparing the obtained results for energy spectrum of the source and percentage depth-dose along the central axis of plaques with the available published data. The delivered doses to the eye components and tumors show that received doses by different eye substructures depend on the size of the plaque and tumor thickness. Results show that the knowledge of the height of tumor apex before treating eye tumors with ophthalmic plaques is essential. On the other hand, about 32% (62%) of the dose deposition belongs to secondary produced photons in the CCA (CCB) plaque. Moreover, comparing the results obtained from two plaques, showed that although the CCB plaque produces a more uniform dose distribution in the tumor, the CCA plaque presents a higher dose delivery to the tumor and a lower one to the critical structures for all three tumor sizes. Therefore, it is recommended to use CCA plaque for eye tumors up to 5 mm height of the apex.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111636"},"PeriodicalIF":1.6,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142852275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-12DOI: 10.1016/j.apradiso.2024.111631
Elham Edalatkhah, Shahryar Badiei
A gamma cell unit is used for gamma irradiation of small volume samples. Due to the sample volume, there is a dose distribution, which is imperative to be known for appropriate irradiation. In this study, samples of agarose Fricke gel dosimeters were prepared for the dose mapping of the gamma cell unit available in our laboratory. To place the dosimeters at precise locations within the irradiation chamber of the gamma cell unit, a specific phantom was designed and fabricated. In this way, the dose distribution was estimated using optical absorbance measurement of the gel dosimeters. For verification, isodose curves were also obtained using Monte Carlo simulations. The results indicate that the central east-west and north-south points in the irradiation chamber have the highest and lowest dose values, respectively. The experimental and simulation ratios of the dose uniformity was calculated to be 1.53 and 1.48, respectively. The accuracy of the dosimeter performance and the system’s calibration quality are confirmed by the good agreement between the simulation and experimental results.
{"title":"Dose mapping of an irradiation chamber of a gamma cell unit using Fricke gel dosimeters and Monte Carlo simulation","authors":"Elham Edalatkhah, Shahryar Badiei","doi":"10.1016/j.apradiso.2024.111631","DOIUrl":"10.1016/j.apradiso.2024.111631","url":null,"abstract":"<div><div>A gamma cell unit is used for gamma irradiation of small volume samples. Due to the sample volume, there is a dose distribution, which is imperative to be known for appropriate irradiation. In this study, samples of agarose Fricke gel dosimeters were prepared for the dose mapping of the gamma cell unit available in our laboratory. To place the dosimeters at precise locations within the irradiation chamber of the gamma cell unit, a specific phantom was designed and fabricated. In this way, the dose distribution was estimated using optical absorbance measurement of the gel dosimeters. For verification, isodose curves were also obtained using Monte Carlo simulations. The results indicate that the central east-west and north-south points in the irradiation chamber have the highest and lowest dose values, respectively. The experimental and simulation ratios of the dose uniformity was calculated to be 1.53 and 1.48, respectively. The accuracy of the dosimeter performance and the system’s calibration quality are confirmed by the good agreement between the simulation and experimental results.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111631"},"PeriodicalIF":1.6,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142862897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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