Applied Radiation and Isotopes最新文献

{"title":"Counting efficiencies of shadow shield whole body counter for adult and paediatric reference computational phantoms","authors":"Rahul Roy,&nbsp;Hemant K. Patni,&nbsp;Pradeep K. Singh,&nbsp;Pramilla D. Sawant","doi":"10.1016/j.apradiso.2025.111667","DOIUrl":"10.1016/j.apradiso.2025.111667","url":null,"abstract":"<div><div>Shadow Shield Whole Body Counter (SSWBC) is used to estimate internal dose of radiation workers due to the intake of fission and activation products. The SSWBC geometry was numerically modelled in FLUKA code. The computational model was validated by comparing the experimental and simulated counting efficiencies (CEs), also known as response, using Bhabha Atomic Research Centre (BARC) reference BOttle Mannequin Absorption (BOMAB) phantom. Monte Carlo simulations were carried out in FLUKA to estimate the response for High Energy Photon emitters (HEPs, E_γ &gt; 200 keV) using adult and paediatric (new-born, 1-year, 5-year, 10-year and 15-year) reference computational phantoms for male and female provided by International Commission on Radiation Protection. The scanning geometry of the system was simulated, scoring energy deposition in a NaI(Tl) detector at 15 static locations along the bed's length. The final response was calculated by averaging the detector responses at 15 static locations obtained from the simulations. The results highlight that the gender-averaged response at 300 keV for 5-year-olds is ∼20% higher than that for adults. For 15-year-olds and adults, female phantoms have 2.4% and 3.8% higher responses than males at 300 keV and, 3.2% and 1.1% higher responses at 1400 keV. From new-born to 10-year response is similar for both genders. The results also highlight that for any age group, response increases up to few detector locations and then it falls sharply. At any energy, the detector location for peak response is different for various age groups. These results will be useful for realistic assessment of HEPs in members of the public during any nuclear or radiological emergency scenarios.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111667"},"PeriodicalIF":1.6,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142982566","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}

{"title":"Genetic algorithm optimized BP neural network for fast reconstruction of three-dimensional radiation field","authors":"Qian Zhang ,&nbsp;Rui Shi ,&nbsp;Rui Gou ,&nbsp;Guang Yang ,&nbsp;Xianguo Tuo","doi":"10.1016/j.apradiso.2025.111668","DOIUrl":"10.1016/j.apradiso.2025.111668","url":null,"abstract":"<div><div>The three-dimensional radiation field is an important database reflecting the radioactivity distribution in a nuclear facility. It is of great significance to accurately and quickly grasp the radiation dose field distribution to implement radiation protection. Presently, majority of radiation field reconstruction algorithms concentrate on two-dimensional reconstruction and can only measure on a regular grid. With the progress of artificial intelligence technology, neural networks have great potential in radiation field reconstruction. In this work, an improved Genetic Algorithm Optimized Backpropagation (GA-BP) neural network was proposed, which can efficiently reconstruct the radiation dose rate at any given position within the three-dimensional space, even under the condition of a low sampling rate. The proposed method achieves a remarkable speed, capable of reconstructing nearly 500 spots in 0.01 s. Two Monte Carlo simulations corresponding to the shielded and unshielded cases verified the effectiveness of the proposed method. The method was further tested on datasets with equally spaced and randomly distributed data points. In both simulation scenarios, the proposed method demonstrated the ability to reconstruct the three-dimensional dose rate field using less than 6% of the data for the simulation cases with a low error level of 3% (unshielded) to 8% (shielded). In the real experimental validation, the error is at 15%, and the point error is less than 30% in most areas.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111668"},"PeriodicalIF":1.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142998958","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}

{"title":"Activity determination of 177Lu using TDCR-Čerenkov method","authors":"Zihao Fan ,&nbsp;Haoran Liu ,&nbsp;Zhijie Yang ,&nbsp;Juncheng Liang ,&nbsp;Changhao Sun ,&nbsp;Yifan Tian","doi":"10.1016/j.apradiso.2025.111660","DOIUrl":"10.1016/j.apradiso.2025.111660","url":null,"abstract":"<div><div>The accuracy of measuring the activity of ¹⁷⁷Lu is crucial for calibrating the instruments employed in clinical applications. To support the measurements of ¹⁷⁷Lu solution, the existing TDCR-Čerenkov method has been extended for this nuclide. The contribution of β and γ transitions from ¹⁷⁷Lu was taken into account in the extended method. Finally, the results obtained using this method, with an uncertainty of 0.62%, were found to be in good agreement with that derived from liquid scintillation counting.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111660"},"PeriodicalIF":1.6,"publicationDate":"2025-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142963470","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}

{"title":"Multi-layer shielding optimization of a high activity 241Am-Be mixed field irradiation facility","authors":"N.A. Kotb ,&nbsp;A.H.M. Solieman ,&nbsp;T. El-Zakla ,&nbsp;T.Z. Amer ,&nbsp;S. Elmeniawi ,&nbsp;M.N.H. Comsan","doi":"10.1016/j.apradiso.2025.111662","DOIUrl":"10.1016/j.apradiso.2025.111662","url":null,"abstract":"<div><div>Neutron and gamma-ray shielding design for a 30Ci (1.11TBq) ²⁴¹Am-Be irradiation facility is studied using MCNP5 Monte Carlo simulation code. The study focuses on the optimization of the shielding layers of the previously planned neutron irradiation facility. The shielding design aims at reducing the effective dose rate down to 10 μSv/h for occupationally exposed workers as recommended by the International Commission on Radiological Protection (ICRP) (20 mSv per year for workers). The dose rate calculations consider not only ²⁴¹Am-Be produced neutrons but also gamma rays from the ²⁴¹Am decay, ¹²C∗ de-excitation, and neutron interaction with source and facility materials. Different materials (paraffin, borated-paraffin, beryllium, copper, tantalum, tungsten, zinc, bismuth, and lead) have been investigated as neutron and gamma shields. The choice of the shielding materials is based on their effectiveness (the total weight of the facility and the cost). Among several configurations, shielding layers consisting of 10 cm paraffin wax, 2.5 cm lead, and 31.5 cm borated-paraffin wax are found sufficient to meet the safety requirements, leading to a cubic facility of 104.2 cm overall length. Some irradiation parameters are estimated for the final design; namely neutron and gamma spectra as well as flux and absorbed dose components. In addition, the occupational exposure is assessed considering ICRP exposure conditions to calculate the effective dose rate along with the isodose distribution.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111662"},"PeriodicalIF":1.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142998961","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}

{"title":"Determination of Westcott g-factors for the assay of non-1/v nuclides using k0-NAA","authors":"Manish Chand ,&nbsp;Subhrojit Bagchi ,&nbsp;Bilal Hassan Khan","doi":"10.1016/j.apradiso.2025.111666","DOIUrl":"10.1016/j.apradiso.2025.111666","url":null,"abstract":"<div><div>This study examines the impact of the Westcott g-factor on the concentration of elements like In, Ir, Re, Yb, Eu and Lu, measured using neutron capture reactions (n,γ), specifically focusing on those reactions, whose thermal neutron capture cross-sections (σ _(n,γ)) deviate from the conventional '1/<em>v</em>' behaviour. These measurements are quantified using <em>k</em>₀-based neutron activation analysis. The Westcott g-factor for the non-1/<em>v</em> nuclides was calculated using the characterized neutron temperature (T_n) at PFTS irradiation channel of KAMINI reactor. This computation involved establishing a correlation between g(T_n) Vs T_n, spanning a range from 0 to 100 °C, derived from the latest ENDF/B-VIII.0 nuclear data library. NJOY21 code package modules like RECONR (Resonance Reconstruction) and BROADR (Doppler Broadening) were used to process the neutron capture cross-section at different temperatures. The impact of g(T_n) on the Lu concentration was found to be highest at 81% and least for the Re at 0.2% using ¹⁸⁵Re isotope.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111666"},"PeriodicalIF":1.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142943319","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}

{"title":"Proton dose deposition in heterogeneous media: A TOPAS Monte Carlo simulation study","authors":"Jie Li ,&nbsp;Xiangli Cui ,&nbsp;Lingling Liu ,&nbsp;Bingbing Li ,&nbsp;Zhenle Fei ,&nbsp;Wei Han","doi":"10.1016/j.apradiso.2025.111665","DOIUrl":"10.1016/j.apradiso.2025.111665","url":null,"abstract":"<div><div>This study investigated the influence of tissue electron density on proton beam dose distribution using TOPAS Monte Carlo simulation. Heterogeneous tissue models composed of 14 materials were constructed to simulate the dose deposition process of a 169.23 MeV proton beam. The study analyzed the relationships between electron density and key parameters such as maximum dose, total dose, and dose distribution. Results showed that increasing electron density led to higher local maximum dose, lower total dose, and decreased Bragg peak depth, range, penumbra width, and full width at half maximum (FWHM). High-density tissues caused a sharp, concentrated Bragg peak at shallower depths, while low-density tissues caused a backward shift and widening of the Bragg peak. Differences in proton energy deposition in various tissues were the fundamental reasons for dose distribution variations. This study quantified the relationship between electron density and proton beam dose distribution, providing a reference for accurate dose calculation and optimization in proton therapy.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111665"},"PeriodicalIF":1.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142969406","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}

{"title":"Age-specific DRLs for pediatric brain CT: A review for exploring the practices in Saudi Arabia","authors":"Lama Mukhled Aljuaid ,&nbsp;Sarah Faiz Althobaiti ,&nbsp;Asmaa Abdullah Althobaiti ,&nbsp;Amani Hameed Alsufyani ,&nbsp;Manal Helal Alotaibi ,&nbsp;Bahaaedin A. Elkhader ,&nbsp;Hamid Osman ,&nbsp;Mohammed Meshal Althoibe ,&nbsp;Bassem M. Raafat ,&nbsp;Haytham A. Dahlawi ,&nbsp;Mayeen Uddin Khandaker","doi":"10.1016/j.apradiso.2025.111664","DOIUrl":"10.1016/j.apradiso.2025.111664","url":null,"abstract":"<div><div>This review explores the establishment of diagnostic reference levels (DRLs) for pediatric brain computed tomography (CT) examinations in Saudi Arabia and compares them with nine other countries. An extensive search strategy was employed across various databases, resulting in the inclusion of 9 studies. The studies included patient-based and phantom-based investigations into DRLs, highlighting variations across age groups and countries. Findings suggest notable differences in CT dose index (CTDI mGy) and dose length product (DLP mGy.cm) values. There was a difference in the classification of age group between Saudi food and drug administration (SFDA) and literature. For the age groups 0–5 years and 6–15 years, the DRLs for the SFDA were as follows: CTDI (28 and 42 mGy) and DLP (482 and 697 mGy cm). The discussion emphasizes the importance of age-specific DRLs to optimize radiation doses while ensuring patient safety and diagnostic efficacy. Recommendations include adopting globally accepted standards for dose optimization and continued research into factors influencing DRL variations. Limitations include varying age groupings among studies and limited access to some relevant literature. Overall, this study underscores the importance of standardizing DRLs for pediatric CT to improve patient care and safety.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111664"},"PeriodicalIF":1.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021731","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}

{"title":"Neutronic and burnup analysis of OECD-NEA MOX fuel benchmark with Dragon5 lattice code","authors":"Zelong Zhao,&nbsp;Yaping Guo,&nbsp;Gu Hu","doi":"10.1016/j.apradiso.2025.111661","DOIUrl":"10.1016/j.apradiso.2025.111661","url":null,"abstract":"<div><div>This paper presents a comprehensive and detailed analysis of the OECD-NEA MOX fuel benchmark based on different nuclear data libraries to investigate the reliability and accuracy of the Dragon5 lattice code developed by École Polytechnique de Montréal for the neutronic analysis of mixed uranium-plutonium oxide (MOX) fuel. The neutronics and burn-up calculations for rectangular pin and assembly geometries filled with different compositions of MOX fuel are computed. The performance of different nuclear data libraries is evaluated. Parameters such as infinite multiplication factor, reactivity change agree very well with the averaged reference values provided by the other institutions when the JEF2.2 library is used. Inventories of major actinides and fission product nuclides at different burn-up depths are also compared with published values at the MOX pin cell and assembly level, results of the Dragon5 lattice code are in agreement with averaged values provided by other codes. Furthermore, the deviation between newer libraries and reference solutions of the benchmark should be attributed to the differences in neutron data. Therefore, the Dragon5 lattice code is reliable for neutronics and burn-up analysis of MOX fuel and can be applied to the neutronic analysis of mixed uranium-plutonium oxide fuel.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111661"},"PeriodicalIF":1.6,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143021746","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}

{"title":"A feasibility study on a small electron linear accelerator-based beam shaping assembly for boron neutron capture therapy","authors":"F. Hiraga ,&nbsp;J. Prateepkaew","doi":"10.1016/j.apradiso.2025.111658","DOIUrl":"10.1016/j.apradiso.2025.111658","url":null,"abstract":"<div><div>We aimed to explore the possibility of realizing a beam shaping assembly (BSA) driven by a 15-kW beam of 33-MeV electrons of an electron linear accelerator (LINAC) when a boronophenylalanine is adopted as a boron carrier. Simulation calculations were performed to design two types of BSAs driven by the small LINAC. The one was an experimental BSA, and the other was a high-performance BSA. Calculations of the RBE dose in a phantom exposed to a beam of the high-performance BSA showed that the therapeutic depth, the advantage depth, and the irradiation time were 5.1 cm, 8.3 cm, and 3421 s, respectively. The experimental BSA was constructed, and neutron measurement experiments were performed to confirm the neutron flux in a phantom irradiated by a beam of the experimental BSA. The experiments confirmed that simulation calculations provide a proper estimate for the axial distribution of a neutron dose in a phantom exposed to a beam of the experimental BSA, and ensured that that the high-performance BSA will deliver effective doses to deep seated lesions in tolerable irradiation times.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111658"},"PeriodicalIF":1.6,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142963354","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}

{"title":"Comparison between the SGRT and the conventional setup method for patients undergoing VMAT for pelvic malignancies","authors":"V. Sotiropoulou ,&nbsp;F. Tsironi ,&nbsp;M. Tolia ,&nbsp;M. Mazonakis","doi":"10.1016/j.apradiso.2025.111659","DOIUrl":"10.1016/j.apradiso.2025.111659","url":null,"abstract":"<div><h3>Purpose</h3><div>Surface Guided Radiation Treatment (SGRT) is a new method of positioning and monitoring patients on the linear accelerator's couch, using visual light cameras to monitor the skin's surface. The purpose of this study was to compare the SGRT with the conventional method, based on lasers and tattoos, in terms of accuracy and time expenditure, on patients with pelvic malignancies.</div></div><div><h3>Materials and methods</h3><div>A group of 34 patients were enrolled in this study, 24 males who underwent radiotherapy prostate treatment and 10 females who underwent gynecological radiation therapy. They were divided into two groups: Group A consisted of 17 (12 males and 5 females) patients positioned using tattoos/laser technique. Group Β also consisted of 17 (12 males and 5 females) patients positioned using the SGRT technique. For the verification of their position, all patients underwent cone beam computed tomography (CBCT) before each session. The corrections in the three directions recorded by the CBCT system were acquired for 419 and 358 sessions for groups A and B, respectively. The total corrections were also calculated. The positioning time was measured for 7 treatment sessions for each patient. The above corrections, along with the positioning duration, were statistically compared between the two groups.</div></div><div><h3>Results</h3><div>The Mann-Whitney <em>U</em> test shows that the corrections for Group B were significantly smaller (p &lt; 0.05) than those for Group A. The comparison of the median values of each dataset shows that the corrections improved by 16.6% for the vertical direction, 36.7% for the lateral direction, and 33.3% for the longitudinal direction, while the total correction improved by 29.2%. The SGRT method also seems more consistent, as the average interquartile range (IQR) of the correction values of Group B was 0.25 cm, while the same value was 0.38 cm for Group A. The median positioning time was 1.6 ± 0.4 min for Group A and 2.0 ± 0.6 min for Group B. The positioning duration of patients in Group B was significantly elevated (Mann-Whitney <em>U</em> test, p &lt; 0.001) in respect to that related to patients of Group A.</div></div><div><h3>Conclusion</h3><div>The above results show that SGRT increases the setup time compared to the conventional approach but it provides a more accurate positioning of patients subjected to VMAT for pelvic malignancies.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"217 ","pages":"Article 111659"},"PeriodicalIF":1.6,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142943318","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}