Pub Date : 2025-12-04DOI: 10.1016/j.apradiso.2025.112352
Dz. Shoukavy , Yu. Kurochkin , A. Naumenko , D. Vasileuskaya , Yingying Zhang , Bingwei Wu
A GEANT4-based Monte Carlo simulation model of an underwater gamma-ray spectrometer based on europium-doped strontium iodide () is developed and validated in this study. The scintillator has superior properties – including excellent energy resolution ( 3% at ), high light yield (90 photons/keV), and minimal intrinsic radioactivity – that make it particularly suitable for aquatic radiation monitoring. The GEANT4 model uses the Penelope physics list for accurate low-energy simulation. A direct comparison was made between the baseline Penelope model and the standard electromagnetic physics list (G4EmStandardPhysics). A comprehensive library of detector response functions (DRFs) was generated, covering gamma-ray energies from to to establish the gamma-ray detection efficiency in the full operation range. Experimental validation is performed in an water tank using calibrated radioactive solutions of 139Ce (gamma-ray energy ), 137Cs (), and 88Y (), which showed excellent agreement ( 1%) with a tank-replication simulation. Another simulation, which used an energy-dependent effective volume () to model an infinite water geometry, revealed a significant 12.5% discrepancy at 1836 keV that is attributed to finite tank volume effects.
{"title":"GEANT4 Monte Carlo simulation and validation of an underwater gamma-ray spectrometer based on SrI2(Eu) scintillator","authors":"Dz. Shoukavy , Yu. Kurochkin , A. Naumenko , D. Vasileuskaya , Yingying Zhang , Bingwei Wu","doi":"10.1016/j.apradiso.2025.112352","DOIUrl":"10.1016/j.apradiso.2025.112352","url":null,"abstract":"<div><div>A GEANT4-based Monte Carlo simulation model of an underwater gamma-ray spectrometer based on europium-doped strontium iodide (<span><math><mrow><msub><mrow><mi>SrI</mi></mrow><mrow><mn>2</mn></mrow></msub><mrow><mo>(</mo><mi>Eu</mi><mo>)</mo></mrow></mrow></math></span>) is developed and validated in this study. The scintillator has superior properties – including excellent energy resolution (<span><math><mo>∼</mo></math></span> 3% at <span><math><mrow><mn>662</mn><mspace></mspace><mtext>keV</mtext></mrow></math></span>), high light yield (90 photons/keV), and minimal intrinsic radioactivity – that make it particularly suitable for aquatic radiation monitoring. The GEANT4 model uses the Penelope physics list for accurate low-energy simulation. A direct comparison was made between the baseline Penelope model and the standard electromagnetic physics list (G4EmStandardPhysics). A comprehensive library of detector response functions (DRFs) was generated, covering gamma-ray energies from <span><math><mrow><mn>50</mn><mspace></mspace><mtext>keV</mtext></mrow></math></span> to <span><math><mrow><mn>3</mn><mspace></mspace><mtext>MeV</mtext></mrow></math></span> to establish the gamma-ray detection efficiency in the full operation range. Experimental validation is performed in an <span><math><mrow><mn>8</mn><mspace></mspace><msup><mrow><mtext>m</mtext></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span> water tank using calibrated radioactive solutions of <sup>139</sup>Ce (gamma-ray energy <span><math><mrow><mn>165</mn><mo>.</mo><mn>8</mn><mspace></mspace><mtext>keV</mtext></mrow></math></span>), <sup>137</sup>Cs (<span><math><mrow><mn>661</mn><mo>.</mo><mn>6</mn><mspace></mspace><mtext>keV</mtext></mrow></math></span>), and <sup>88</sup>Y (<span><math><mrow><mn>898</mn><mo>.</mo><mn>0</mn><mspace></mspace><mtext>and</mtext><mspace></mspace><mn>1836</mn><mo>.</mo><mn>0</mn><mspace></mspace><mtext>keV</mtext></mrow></math></span>), which showed excellent agreement ( 1%) with a tank-replication simulation. Another simulation, which used an energy-dependent effective volume (<span><math><mrow><msub><mrow><mi>V</mi></mrow><mrow><mi>e</mi></mrow></msub><mi>f</mi><mi>f</mi></mrow></math></span>) to model an infinite water geometry, revealed a significant 12.5% discrepancy at 1836 keV that is attributed to finite tank volume effects.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112352"},"PeriodicalIF":1.8,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145712996","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 : 2025-12-03DOI: 10.1016/j.apradiso.2025.112364
Li Li , Yingtong Fang , Yaping Zhao , Zhaoqing Zhang , Yadong Zhang , Juncheng Liang , Liudong Hou , Quanwei Liu , Yongquan Qin , Yantao Hu
Accurate and rapid online measurement of alpha radioactivity in radioactive solutions poses significant challenges in the nuclear industry. Conventional methods are often limited by susceptibility to detector contamination, operational complexity, and difficulties in real-time monitoring and calibration. This study presents an innovative online device and methodology based on a rotating-wheel liquid-film technique. A precision wheel generates a stable, uniform ∼100-micron-thick liquid film on its polished surface, enabling direct alpha detection. Optimization of wheel surface finish and rotation speed ensured reproducible film thickness. An integrated compressed air purge system effectively shields the detector from aerosols, preventing background accumulation during extended operation. Crucially, a built-in calibration disk facilitates online measurement calibration. A specially designed high-efficiency ZnS(Ag) scintillation detector enhances detection efficiency while ensuring stability. The performance of the online measurement device was evaluated using a plutonium-containing organic phase solution as the test material. It demonstrated excellent linearity (R2 = 0.9996) across a wide activity range of 1.16 × 106 to 1.16 × 109 Bq·L−1. Precision (relative standard deviation, RSD) was ≤2.61 %, with a detection limit of 1.45 × 104 Bq·L−1. The device maintained good stability (RSD = 1.91 %) during a 10-day continuous operation test. This device exhibits superior detection efficiency, contamination resistance, online calibration capability, and long-term stability, meeting the stringent demands for high-precision, real-time α monitoring in complex radiochemical streams.
{"title":"Development of online measurement technology for total alpha activity in radioactive solution based on liquid film","authors":"Li Li , Yingtong Fang , Yaping Zhao , Zhaoqing Zhang , Yadong Zhang , Juncheng Liang , Liudong Hou , Quanwei Liu , Yongquan Qin , Yantao Hu","doi":"10.1016/j.apradiso.2025.112364","DOIUrl":"10.1016/j.apradiso.2025.112364","url":null,"abstract":"<div><div>Accurate and rapid online measurement of alpha radioactivity in radioactive solutions poses significant challenges in the nuclear industry. Conventional methods are often limited by susceptibility to detector contamination, operational complexity, and difficulties in real-time monitoring and calibration. This study presents an innovative online device and methodology based on a rotating-wheel liquid-film technique. A precision wheel generates a stable, uniform ∼100-micron-thick liquid film on its polished surface, enabling direct alpha detection. Optimization of wheel surface finish and rotation speed ensured reproducible film thickness. An integrated compressed air purge system effectively shields the detector from aerosols, preventing background accumulation during extended operation. Crucially, a built-in calibration disk facilitates online measurement calibration. A specially designed high-efficiency ZnS(Ag) scintillation detector enhances detection efficiency while ensuring stability. The performance of the online measurement device was evaluated using a plutonium-containing organic phase solution as the test material. It demonstrated excellent linearity (R<sup>2</sup> = 0.9996) across a wide activity range of 1.16 × 10<sup>6</sup> to 1.16 × 10<sup>9</sup> Bq·L<sup>−1</sup>. Precision (relative standard deviation, RSD) was ≤2.61 %, with a detection limit of 1.45 × 10<sup>4</sup> Bq·L<sup>−1</sup>. The device maintained good stability (RSD = 1.91 %) during a 10-day continuous operation test. This device exhibits superior detection efficiency, contamination resistance, online calibration capability, and long-term stability, meeting the stringent demands for high-precision, real-time α monitoring in complex radiochemical streams.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112364"},"PeriodicalIF":1.8,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682644","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 : 2025-12-03DOI: 10.1016/j.apradiso.2025.112369
Yadong Zhang , Jinjia Cao , Xiaochang Zheng , Yanjun Wang , Yulong Zhang , Wei Chen , Huajun Yuan
The mass attenuation coefficient (MAC) plays a key parameter in computed tomography (CT) imaging and the development of novel contrast agents. In practical applications, the MAC depends not only on photon energy but also on complex, interrelated factors such as material composition, contrast agent concentration, and mixture density, exhibiting pronounced nonlinear characteristics. Existing theoretical databases and pointwise simulation methods are often inadequate for rapid, high-resolution predictions across broad parameter spaces. In this work, we propose a new, high-throughput MAC prediction framework that integrates high-resolution Geant4 Monte Carlo simulations with a random forest machine learning regression model. The X-ray attenuation properties of contrast agent–water mixtures were systematically modeled under varying photon energies, molecular weights, concentrations, electron densities, and bulk densities, producing a comprehensive and high-resolution simulation dataset within clinically relevant energy and concentration ranges. Using five key physical parameters as input, the random forest model was trained with normalized preprocessing, grid search hyperparameter optimization, and K-fold cross-validation, yielding good generalization and predictive performance. The proposed method demonstrated strong agreement with Monte Carlo simulations for both training and test sets, as indicated by R2, MAE, and RMSE metrics, while improving computational efficiency for large-sample, multivariable cases. Compared with conventional approaches, this study establishes—for the first time—a high-resolution simulation dataset encompassing the major parameter ranges relevant to CT imaging, and realizes a stable, scalable MAC prediction framework based on machine learning. The developed framework enables automated, high-throughput MAC estimation across vast, multi-dimensional parameter spaces, facilitating real-time adaptation to diverse clinical or engineering scenarios.
{"title":"An efficient method for determining the mass attenuation coefficient of contrast agent–water mixtures and analysis of influencing factors in medical imaging systems","authors":"Yadong Zhang , Jinjia Cao , Xiaochang Zheng , Yanjun Wang , Yulong Zhang , Wei Chen , Huajun Yuan","doi":"10.1016/j.apradiso.2025.112369","DOIUrl":"10.1016/j.apradiso.2025.112369","url":null,"abstract":"<div><div>The mass attenuation coefficient (MAC) plays a key parameter in computed tomography (CT) imaging and the development of novel contrast agents. In practical applications, the MAC depends not only on photon energy but also on complex, interrelated factors such as material composition, contrast agent concentration, and mixture density, exhibiting pronounced nonlinear characteristics. Existing theoretical databases and pointwise simulation methods are often inadequate for rapid, high-resolution predictions across broad parameter spaces. In this work, we propose a new, high-throughput MAC prediction framework that integrates high-resolution Geant4 Monte Carlo simulations with a random forest machine learning regression model. The X-ray attenuation properties of contrast agent–water mixtures were systematically modeled under varying photon energies, molecular weights, concentrations, electron densities, and bulk densities, producing a comprehensive and high-resolution simulation dataset within clinically relevant energy and concentration ranges. Using five key physical parameters as input, the random forest model was trained with normalized preprocessing, grid search hyperparameter optimization, and K-fold cross-validation, yielding good generalization and predictive performance. The proposed method demonstrated strong agreement with Monte Carlo simulations for both training and test sets, as indicated by R<sup>2</sup>, MAE, and RMSE metrics, while improving computational efficiency for large-sample, multivariable cases. Compared with conventional approaches, this study establishes—for the first time—a high-resolution simulation dataset encompassing the major parameter ranges relevant to CT imaging, and realizes a stable, scalable MAC prediction framework based on machine learning. The developed framework enables automated, high-throughput MAC estimation across vast, multi-dimensional parameter spaces, facilitating real-time adaptation to diverse clinical or engineering scenarios.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112369"},"PeriodicalIF":1.8,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682643","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 : 2025-12-02DOI: 10.1016/j.apradiso.2025.112355
Sami Ullah , Anwar Manzoor Rana , Kainat Sindhu , Javed Ahmad , Maryam Hina , M.I. Sayyed
The zinc-tellurium-bismuth-borate glass system has been synthesized, and its physical, optical, dielectric, and radiation attenuation properties have been investigated. Experimental outcomes reveal that density and bandgap energy express an increasing trend with increasing ZnO content in these glasses. DC conductivity discloses space-charge-limited conduction behavior, which changes to Ohmic conduction with increasing ZnO concentration. AC conductivity also depicts changing behavior from ionic to hopping conduction of charge carriers with rising ZnO content in these glasses. The MAC values demonstrate a rising trend from 46.38 cm2/g to 56.73 cm2/g, while HVL and mean free path reveal a reduction from 3.477 cm to 2.885 cm and from 5.016 cm to 4.162 cm, respectively, as the ZnO content in these glasses increases. The BZBT6 glass exhibits radiation shielding characteristics comparable to those of commercially available lead-containing glass (RS-520) and appears to be suitable as a gamma-radiation shield at intermediate energies.
{"title":"Impact of ZnO on the dielectric, optical and γ-ray shielding characteristics of TeO2–Bi2O3– B2O3 glasses","authors":"Sami Ullah , Anwar Manzoor Rana , Kainat Sindhu , Javed Ahmad , Maryam Hina , M.I. Sayyed","doi":"10.1016/j.apradiso.2025.112355","DOIUrl":"10.1016/j.apradiso.2025.112355","url":null,"abstract":"<div><div>The zinc-tellurium-bismuth-borate glass system has been synthesized, and its physical, optical, dielectric, and radiation attenuation properties have been investigated. Experimental outcomes reveal that density and bandgap energy express an increasing trend with increasing ZnO content in these glasses. DC conductivity discloses space-charge-limited conduction behavior, which changes to Ohmic conduction with increasing ZnO concentration. AC conductivity also depicts changing behavior from ionic to hopping conduction of charge carriers with rising ZnO content in these glasses. The MAC values demonstrate a rising trend from 46.38 cm<sup>2</sup>/g to 56.73 cm<sup>2</sup>/g, while HVL and mean free path reveal a reduction from 3.477 cm to 2.885 cm and from 5.016 cm to 4.162 cm, respectively, as the ZnO content in these glasses increases. The BZBT6 glass exhibits radiation shielding characteristics comparable to those of commercially available lead-containing glass (RS-520) and appears to be suitable as a gamma-radiation shield at intermediate energies.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112355"},"PeriodicalIF":1.8,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145720764","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 : 2025-12-02DOI: 10.1016/j.apradiso.2025.112349
Bashiru Lukuman , Husain Murat , Mohamad Aminuddin Said , Yazid Yaakob , Mohamad Johari Ibahim , Dahlang Tahir , Muhammad Khalis Abdul Karim
This study evaluates the influence of body-mass index (BMI) on radiation dosimetry in PET/CT procedures, focusing on radiation dose variations across BMI categories. Data were collected from 1000 patients at Institut Kanser Negara, Malaysia, comprising 516 females (51.6 %) and 484 males (48.4 %) who underwent whole body 18F-FDG PET/CT procedures from July 2023 to December 2023. Parameters such as administered dose, CTDIvol, DLP, and effective dose were analysed. The findings indicate that CTDIvol and DLP values increase with BMI, imposing higher radiation doses for larger patients to maintain diagnostic image quality. Administered doses showed minimal variability across different BMI categories and genders, reflecting standardized radiotracer administration protocols. Male patients generally received higher radiation doses than female patients due to differences in body composition and size. Effective dose (ECT) from CT scans was significantly higher in patients with higher BMI, ranging from 7.1 ± 2.4 mSv for underweight to 19.3 ± 4.7 mSv for obese patients. Effective dose (EPET) from PET scans remained relatively consistent across BMI categories, ranging from 0.2 ± 0.07 mSv for underweight to 0.2 ± 0.07 mSv for obese patients, highlighting the need for personalized dosing techniques. All pairwise differences were statistically significant at p > 0.001. This study underscores the necessity for personalized dosimetry protocols that account for BMI variations to optimize imaging quality while minimizing radiation exposure. The study recommends developing and implementing such protocols and establishing guidelines for radiopharmaceutical dosage adjustments based on BMI categories to ensure standardized and safe practices across clinical settings.
{"title":"Impact of body-mass-index (BMI) on effective dose of whole-body [18F] fluorodeoxyglucose PET/CT examinations","authors":"Bashiru Lukuman , Husain Murat , Mohamad Aminuddin Said , Yazid Yaakob , Mohamad Johari Ibahim , Dahlang Tahir , Muhammad Khalis Abdul Karim","doi":"10.1016/j.apradiso.2025.112349","DOIUrl":"10.1016/j.apradiso.2025.112349","url":null,"abstract":"<div><div>This study evaluates the influence of body-mass index (BMI) on radiation dosimetry in PET/CT procedures, focusing on radiation dose variations across BMI categories. Data were collected from 1000 patients at Institut Kanser Negara, Malaysia, comprising 516 females (51.6 %) and 484 males (48.4 %) who underwent whole body <sup>18</sup>F-FDG PET/CT procedures from July 2023 to December 2023. Parameters such as administered dose, CTDI<sub>vol</sub>, DLP, and effective dose were analysed. The findings indicate that CTDI<sub>vol</sub> and DLP values increase with BMI, imposing higher radiation doses for larger patients to maintain diagnostic image quality. Administered doses showed minimal variability across different BMI categories and genders, reflecting standardized radiotracer administration protocols. Male patients generally received higher radiation doses than female patients due to differences in body composition and size. Effective dose (E<sub>CT</sub>) from CT scans was significantly higher in patients with higher BMI, ranging from 7.1 ± 2.4 mSv for underweight to 19.3 ± 4.7 mSv for obese patients. Effective dose (E<sub>PET</sub>) from PET scans remained relatively consistent across BMI categories, ranging from 0.2 ± 0.07 mSv for underweight to 0.2 ± 0.07 mSv for obese patients, highlighting the need for personalized dosing techniques. All pairwise differences were statistically significant at p > 0.001. This study underscores the necessity for personalized dosimetry protocols that account for BMI variations to optimize imaging quality while minimizing radiation exposure. The study recommends developing and implementing such protocols and establishing guidelines for radiopharmaceutical dosage adjustments based on BMI categories to ensure standardized and safe practices across clinical settings.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112349"},"PeriodicalIF":1.8,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682649","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}
Positron emission tomography (PET) scanner for small animals is of great importance for developing new radiopharmaceuticals for molecular diagnosis and therapy and, thus, for potential clinical applications. The calibration procedure of these systems is essential for quantitative studies and image quality evaluation. It requires several steps, materials, and a suitable phantom. This study aimed to develop a 3D-printed mouse phantom based on the DM_BRA voxel mouse phantom and demonstrate its applicability for small animal PET studies. The physical mouse phantom consists of the 3D printing of a minimum of 2 mm thick with an empty internal cavity corresponding to the real dimensions of the DM_BRA voxel phantom. The model was impermeabilized with epoxy resin to prevent leakage. Counting efficiency and count rates performance evaluations were conducted using the PET scanner (LabPET4 Solo, GE Healthcare Technologies) at the Molecular Image Laboratory (LIM/CDTN/CNEN) in Brazil. Tests revealed that the counting efficiency of the system is about 6.4kCPS·MBq−1. In general, the absolute values from DM_BRA zoomorphic phantom count rates curves are lower than those from the recommended NEMA NU 4–2008 cylindrical phantom. However, the shape of the count rates curves from both phantoms are very similar: (i) prompt curves increase up to their maximum value at 100MBq and after decrease slowly to around 90 % of the maximum value at 180MBq; (ii) true curves reached their maximum value around 100MBq, corresponding to 50 % of prompt counts; (iii) random curves reach similar plateau value around 50 % of prompt counts; (iv) NEC curves in both studies reach their maximum value at 90MBq. The study revealed that despite the lower counts rates performance, the zoomorphic model offers an anatomically representative design. Its adaptability for different radionuclides and straightforward preparation enhances its usability in routine laboratory protocols.
小动物正电子发射断层扫描（PET）对于开发新的放射性药物用于分子诊断和治疗具有重要意义，因此具有潜在的临床应用价值。这些系统的校准过程对于定量研究和图像质量评估至关重要。它需要几个步骤、材料和一个合适的模型。本研究旨在开发基于DM_BRA体素小鼠体素的3d打印小鼠体模，并验证其在小动物PET研究中的适用性。物理鼠标幻影由至少2毫米厚的3D打印组成，其内部空腔与DM_BRA体素幻影的实际尺寸相对应。模型采用环氧树脂防渗，防止渗漏。在巴西分子图像实验室（LIM/CDTN/CNEN）使用PET扫描仪（LabPET4 Solo, GE Healthcare Technologies）进行计数效率和计数率性能评估。测试结果表明，该系统的计数效率约为6.4kCPS·MBq−1。一般来说，DM_BRA兽形幻体计数率曲线的绝对值低于推荐的NEMA NU 4-2008圆柱形幻体计数率曲线的绝对值。然而，两个幻影的计数率曲线的形状非常相似：(i)提示曲线在100MBq时增加到最大值，然后在180MBq时缓慢下降到最大值的90%左右；（ii）真实曲线在100MBq左右达到最大值，相当于50%的提示计数；（iii）随机曲线在提示计数的50%左右达到相似的平台值；（iv）两项研究的NEC曲线在90MBq时达到最大值。研究表明，尽管计数率较低，但动物模型提供了解剖学上具有代表性的设计。它对不同放射性核素的适应性和简单的制备增强了它在常规实验室方案中的可用性。
{"title":"A prototype of a 3D-printed zoomorphic mouse model for small animal PET scanner calibration","authors":"E.M.R. Andrade , A.C.M. Silva , A.V. Ferreira , R.M.G. Gontijo , L. Paixão , T.C.F. Fonseca , B.M. Mendes","doi":"10.1016/j.apradiso.2025.112362","DOIUrl":"10.1016/j.apradiso.2025.112362","url":null,"abstract":"<div><div>Positron emission tomography (PET) scanner for small animals is of great importance for developing new radiopharmaceuticals for molecular diagnosis and therapy and, thus, for potential clinical applications. The calibration procedure of these systems is essential for quantitative studies and image quality evaluation. It requires several steps, materials, and a suitable phantom. This study aimed to develop a 3D-printed mouse phantom based on the DM_BRA voxel mouse phantom and demonstrate its applicability for small animal PET studies. The physical mouse phantom consists of the 3D printing of a minimum of 2 mm thick with an empty internal cavity corresponding to the real dimensions of the DM_BRA voxel phantom. The model was impermeabilized with epoxy resin to prevent leakage. Counting efficiency and count rates performance evaluations were conducted using the PET scanner (LabPET4 Solo, GE Healthcare Technologies) at the Molecular Image Laboratory (LIM/CDTN/CNEN) in Brazil. Tests revealed that the counting efficiency of the system is about 6.4kCPS·MBq<sup>−1</sup>. In general, the absolute values from DM_BRA zoomorphic phantom count rates curves are lower than those from the recommended NEMA NU 4–2008 cylindrical phantom. However, the shape of the count rates curves from both phantoms are very similar: (i) prompt curves increase up to their maximum value at 100MBq and after decrease slowly to around 90 % of the maximum value at 180MBq; (ii) true curves reached their maximum value around 100MBq, corresponding to 50 % of prompt counts; (iii) random curves reach similar plateau value around 50 % of prompt counts; (iv) NEC curves in both studies reach their maximum value at 90MBq. The study revealed that despite the lower counts rates performance, the zoomorphic model offers an anatomically representative design. Its adaptability for different radionuclides and straightforward preparation enhances its usability in routine laboratory protocols.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112362"},"PeriodicalIF":1.8,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682646","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 : 2025-12-02DOI: 10.1016/j.apradiso.2025.112358
Kevser A. Hışıroğlu, Özgür Akçalı, Ozan Toker, Orhan İçelli
This study investigates the beta radiation shielding and transmission performance of transparent polymers and glasses used as protective layers in commercial p-i-n diodes for betavoltaic systems. To the best of our knowledge, this study presents the first comprehensive application of the Half Absorption Thickness (HAT) metric to transparent polymers and glasses, providing a novel quantitative parameter for optimizing beta shielding performance. MCNP6.2 simulations were performed for seven beta sources (3H, 63Ni, 14C, 147Pm, 90Sr, 90Y, 99Tc) and five materials (PMMA, SMMA, PC, Pyrex, glass) over nanometer-millimeter thicknesses. Transmission strongly depended on material type and source energy; glass attenuated 94 % of 3H at sub-micron thickness, while PC transmitted over 30 %. The Half Absorption Thickness (HAT) metric revealed nanoscale attenuation differences, such as <200 nm for 3H in glass versus >600 nm in PC. Logarithmic regression models (R2 > 0.99) allow rapid performance estimation, providing a quantitative basis for material selection in betavoltaic batteries, medical diagnostics, aerospace sensors, and radiation-hardened electronics.
{"title":"Comparative Monte Carlo study of transparent protective layers for beta radiation attenuation in betavoltaic applications","authors":"Kevser A. Hışıroğlu, Özgür Akçalı, Ozan Toker, Orhan İçelli","doi":"10.1016/j.apradiso.2025.112358","DOIUrl":"10.1016/j.apradiso.2025.112358","url":null,"abstract":"<div><div>This study investigates the beta radiation shielding and transmission performance of transparent polymers and glasses used as protective layers in commercial p-i-n diodes for betavoltaic systems. To the best of our knowledge, this study presents the first comprehensive application of the Half Absorption Thickness (HAT) metric to transparent polymers and glasses, providing a novel quantitative parameter for optimizing beta shielding performance. MCNP6.2 simulations were performed for seven beta sources (<sup>3</sup>H, <sup>63</sup>Ni, <sup>14</sup>C, <sup>147</sup>Pm, <sup>90</sup>Sr, <sup>90</sup>Y, <sup>99</sup>Tc) and five materials (PMMA, SMMA, PC, Pyrex, glass) over nanometer-millimeter thicknesses. Transmission strongly depended on material type and source energy; glass attenuated 94 % of <sup>3</sup>H at sub-micron thickness, while PC transmitted over 30 %. The Half Absorption Thickness (HAT) metric revealed nanoscale attenuation differences, such as <200 nm for <sup>3</sup>H in glass versus >600 nm in PC. Logarithmic regression models (R<sup>2</sup> > 0.99) allow rapid performance estimation, providing a quantitative basis for material selection in betavoltaic batteries, medical diagnostics, aerospace sensors, and radiation-hardened electronics.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112358"},"PeriodicalIF":1.8,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145712948","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 : 2025-12-02DOI: 10.1016/j.apradiso.2025.112357
Sonika Thakur , Parminder Kaur
With an increasing use of nuclear radiation in medical, industrial, and research fields, effective shielding materials are essential to minimize the risks of radiation exposure. This study explores polyaniline (PA) enhanced with the heavy metal oxide cobalt ferrite (CoFe2O4 or CoFe) as a potential lightweight, flexible, non-toxic shielding material. The gamma-ray attenuation efficiency of these composites was analysed across the energy range 0.015–15 MeV at 31 discrete photon energies with the help of Phy-X/PSD software. The results were further validated using the XCOM software. Additionally, shielding against fast neutrons was studied for the prepared samples and was also compared with the commercially available radiation shielding materials. Results indicate that with cobalt ferrite incorporation, S2 (0.6 wt% CoFe) exhibited 34.96 % higher FNRC than S0 (0 wt% CoFe) and 15.96 % better HVL reduction than PVC. The studied PA-CoFe composites exhibit promising radiation shielding capabilities. They can be effectively utilized as lightweight, flexible shielding panels, coatings, casings, and protective barriers in nuclear reactors, medical radiotherapy, and other radiation-intensive environments.
{"title":"Shielding performance of polyaniline-cobalt ferrite composite materials against hazardous gamma-rays and fast neutrons","authors":"Sonika Thakur , Parminder Kaur","doi":"10.1016/j.apradiso.2025.112357","DOIUrl":"10.1016/j.apradiso.2025.112357","url":null,"abstract":"<div><div>With an increasing use of nuclear radiation in medical, industrial, and research fields, effective shielding materials are essential to minimize the risks of radiation exposure. This study explores polyaniline (PA) enhanced with the heavy metal oxide cobalt ferrite (CoFe<sub>2</sub>O<sub>4</sub> or CoFe) as a potential lightweight, flexible, non-toxic shielding material. The gamma-ray attenuation efficiency of these composites was analysed across the energy range 0.015–15 MeV at 31 discrete photon energies with the help of Phy-X/PSD software. The results were further validated using the XCOM software. Additionally, shielding against fast neutrons was studied for the prepared samples and was also compared with the commercially available radiation shielding materials. Results indicate that with cobalt ferrite incorporation, S<sub>2</sub> (0.6 wt% CoFe) exhibited 34.96 % higher FNRC than S<sub>0</sub> (0 wt% CoFe) and 15.96 % better HVL reduction than PVC. The studied PA-CoFe composites exhibit promising radiation shielding capabilities. They can be effectively utilized as lightweight, flexible shielding panels, coatings, casings, and protective barriers in nuclear reactors, medical radiotherapy, and other radiation-intensive environments.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112357"},"PeriodicalIF":1.8,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682648","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 : 2025-12-02DOI: 10.1016/j.apradiso.2025.112359
Qin Yi , Tingfeng Zhang , Chuqiao Luo , Jinhua Wang , Lin Li , Hong Hu , Jie Ma
Background
Neoadjuvant chemotherapy (NAC) downstage breast cancer and increases breast-conserving surgery rates, but response variability challenges early efficacy prediction. While Residual Cancer Burden (RCB) is a robust post-NAC prognostic marker, its imaging and molecular determinants remain unclear. We investigated MRI-based tumor spatial heterogeneity related to RCB classification and identified radiogenomic biomarkers of treatment response.
Methods
Retrospective analysis of 375 breast cancer patients receiving NAC and surgery, stratified into RCB-0/I and RCB-II/III groups from two centers. Pre-treatment dynamic contrast-enhanced MRI enabled radiomic feature extraction and subregional analysis via unsupervised clustering. A support vector machine classifier predicted RCB classes. Radiogenomic associations integrated transcriptomic data using weighted gene co-expression network analysis (WGCNA), gene perturbation similarity analysis and Comparative Toxicogenomics Database. Meta-analysis of 21 cohorts evaluated GATA3 prognostic value.
Results
The radiomics model yield AUCs of 0.92, 0.87 and 0.87 in training set, test set and external validation set, respectively. High-RCB tumors exhibited greater texture heterogeneity, irregular shape, and signal variance. Radiogenomic correlations identified GATA3, CXCR4, CCND1, and VEGF as key genes linked to imaging phenotypes. GATA3 downregulation correlated with aggressive radiomic features and high RCB, confirmed by GPSA. Comparative Toxicogenomics Database analysis suggested environmental modulation. Meta-analysis associated high GATA3 expression with improved recurrence-free survival (HR = 0.50, 95 %CI:0.40–0.64, p < 0.0001).
Conclusions
MRI radiomic subregional analysis captures spatial heterogeneity linked to NAC response. GATA3 serves as a radiogenomic biomarker linking imaging phenotypes to transcriptomic programs. Integrating imaging, genomic, and environmental data may refine personalized response prediction.
背景：新辅助化疗（NAC）降低了乳腺癌的发展阶段，增加了保乳手术的发生率，但反应的可变性对早期疗效预测提出了挑战。虽然残余癌症负担（RCB）是nac后的一个强有力的预后标志物，但其影像学和分子决定因素尚不清楚。我们研究了与RCB分类相关的基于mri的肿瘤空间异质性，并确定了治疗反应的放射基因组生物标志物。方法回顾性分析来自两个中心的375例接受NAC和手术的乳腺癌患者，分为RCB-0/I组和RCB-II/III组。预处理动态对比增强MRI通过无监督聚类实现放射特征提取和分区域分析。支持向量机分类器预测RCB类。放射基因组学协会使用加权基因共表达网络分析（WGCNA）、基因扰动相似性分析和比较毒物基因组学数据库整合转录组数据。21个队列的荟萃分析评估了GATA3的预后价值。结果放射组学模型在训练集、测试集和外部验证集的auc分别为0.92、0.87和0.87。高rcb肿瘤表现出更大的质地异质性、不规则形状和信号差异。放射基因组学相关性发现GATA3、CXCR4、CCND1和VEGF是与成像表型相关的关键基因。GPSA证实，GATA3下调与侵袭性放射学特征和高RCB相关。比较毒物基因组学数据库分析表明环境调节。meta分析表明，高GATA3表达与改善无复发生存率相关（HR = 0.50, 95% CI: 0.40-0.64, p < 0.0001）。结论smri放射学分区域分析捕获了与NAC反应相关的空间异质性。GATA3作为一种放射基因组生物标志物，将成像表型与转录组学程序联系起来。整合成像、基因组和环境数据可以改进个性化的反应预测。
{"title":"MRI subregional analysis of spatial heterogeneity across residual cancer burden levels in breast cancer","authors":"Qin Yi , Tingfeng Zhang , Chuqiao Luo , Jinhua Wang , Lin Li , Hong Hu , Jie Ma","doi":"10.1016/j.apradiso.2025.112359","DOIUrl":"10.1016/j.apradiso.2025.112359","url":null,"abstract":"<div><h3>Background</h3><div>Neoadjuvant chemotherapy (NAC) downstage breast cancer and increases breast-conserving surgery rates, but response variability challenges early efficacy prediction. While Residual Cancer Burden (RCB) is a robust post-NAC prognostic marker, its imaging and molecular determinants remain unclear. We investigated MRI-based tumor spatial heterogeneity related to RCB classification and identified radiogenomic biomarkers of treatment response.</div></div><div><h3>Methods</h3><div>Retrospective analysis of 375 breast cancer patients receiving NAC and surgery, stratified into RCB-0/I and RCB-II/III groups from two centers. Pre-treatment dynamic contrast-enhanced MRI enabled radiomic feature extraction and subregional analysis via unsupervised clustering. A support vector machine classifier predicted RCB classes. Radiogenomic associations integrated transcriptomic data using weighted gene co-expression network analysis (WGCNA), gene perturbation similarity analysis and Comparative Toxicogenomics Database. Meta-analysis of 21 cohorts evaluated GATA3 prognostic value.</div></div><div><h3>Results</h3><div>The radiomics model yield AUCs of 0.92, 0.87 and 0.87 in training set, test set and external validation set, respectively. High-RCB tumors exhibited greater texture heterogeneity, irregular shape, and signal variance. Radiogenomic correlations identified GATA3, CXCR4, CCND1, and VEGF as key genes linked to imaging phenotypes. GATA3 downregulation correlated with aggressive radiomic features and high RCB, confirmed by GPSA. Comparative Toxicogenomics Database analysis suggested environmental modulation. Meta-analysis associated high GATA3 expression with improved recurrence-free survival (HR = 0.50, 95 %CI:0.40–0.64, p < 0.0001).</div></div><div><h3>Conclusions</h3><div>MRI radiomic subregional analysis captures spatial heterogeneity linked to NAC response. GATA3 serves as a radiogenomic biomarker linking imaging phenotypes to transcriptomic programs. Integrating imaging, genomic, and environmental data may refine personalized response prediction.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112359"},"PeriodicalIF":1.8,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733560","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 : 2025-12-02DOI: 10.1016/j.apradiso.2025.112351
Holden Walker, Braden Goddard
This work discusses the development of a tool for the instant modeling and analysis of neutron emissions for a single pebble nuclear fuel removed from the core of a Pebble Bed Reactor (PBR). The creation of this tool utilized computer codes SOURCES-4C and MCNP6.3 to generate data for converting any pebble's actinide masses into an energy-dependent neutron emission rate. This modeling method tackled unique challenges, primarily due to the small geometry of the TRi-structural ISOtropic (TRISO) particles within the fuel. The generated tool is capable of producing an energy-dependent neutron emission spectra for an entire pebble, or from the individual contribution of actinides within a pebble. Using the tool, estimations of a pebble that underwent 1304 days of burn time resulted in a total of 56,799 neutrons per second. Based on a plot of neutron emission over pebble burnup time generated by this tool, neutron detection in PBRs can be used to evaluate pebble cycling decisions for online refueling methods. Additionally, the ability to provide individual actinide neutron emission from pebbles aids waste management decisions for classifying the waste, as well as considering safety concerns in accident analyses.
{"title":"Analysis of neutron emissions from pebble nuclear fuels","authors":"Holden Walker, Braden Goddard","doi":"10.1016/j.apradiso.2025.112351","DOIUrl":"10.1016/j.apradiso.2025.112351","url":null,"abstract":"<div><div>This work discusses the development of a tool for the instant modeling and analysis of neutron emissions for a single pebble nuclear fuel removed from the core of a Pebble Bed Reactor (PBR). The creation of this tool utilized computer codes SOURCES-4C and MCNP6.3 to generate data for converting any pebble's actinide masses into an energy-dependent neutron emission rate. This modeling method tackled unique challenges, primarily due to the small geometry of the TRi-structural ISOtropic (TRISO) particles within the fuel. The generated tool is capable of producing an energy-dependent neutron emission spectra for an entire pebble, or from the individual contribution of actinides within a pebble. Using the tool, estimations of a pebble that underwent 1304 days of burn time resulted in a total of 56,799 neutrons per second. Based on a plot of neutron emission over pebble burnup time generated by this tool, neutron detection in PBRs can be used to evaluate pebble cycling decisions for online refueling methods. Additionally, the ability to provide individual actinide neutron emission from pebbles aids waste management decisions for classifying the waste, as well as considering safety concerns in accident analyses.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"229 ","pages":"Article 112351"},"PeriodicalIF":1.8,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145712928","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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