Applied Radiation and Isotopes最新文献

{"title":"Study of the influence of moderator material on sensitivity of the epithermal neutron flux detector using the 71Ga(n,γ)72Ga reaction","authors":"E. Byambatseren ,&nbsp;T. Bykov ,&nbsp;D. Kasatov ,&nbsp;Ia Kolesnikov ,&nbsp;S. Savinov ,&nbsp;T. Shein ,&nbsp;S. Taskaev","doi":"10.1016/j.apradiso.2025.111844","DOIUrl":"10.1016/j.apradiso.2025.111844","url":null,"abstract":"<div><div>An intense epithermal neutron flux is necessary for boron neutron capture therapy (BNCT), a promising technique for the treatment of malignant tumors. The epithermal neutron flux is an essential characteristic of the BNCT neutron beam, and its measurement is directly related to the reliability of the treatment planning system. Such a tool could be a cylindrical activation detector using ⁷¹Ga (n,γ)⁷²Ga reaction. In the detector, the activation material is positioned in the geometrical center of a cylinder moderator covered with cadmium foil. Two different teams of researchers calculated the sensitivities of detectors of the same size, but with different moderators which differ by a factor of 1.6. In this work, the effect of the moderator material on the sensitivity of the detector was experimentally studied.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"222 ","pages":"Article 111844"},"PeriodicalIF":1.6,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842628","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":"Novel adaptation of the BeOSL whole-body dosimeter for the measurement of the ICRU 95 quantity Hp","authors":"Gabriela T.P. Melo ,&nbsp;Helen J. Khoury ,&nbsp;Viviane K. Asfora ,&nbsp;Gabriel H.R.B. França ,&nbsp;Vinicius S.M. de Barros","doi":"10.1016/j.apradiso.2025.111839","DOIUrl":"10.1016/j.apradiso.2025.111839","url":null,"abstract":"","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"222 ","pages":"Article 111839"},"PeriodicalIF":1.6,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842629","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":"Comparative efficacy of reactor vs. accelerator-based boron neutron capture therapy in U87MG glioblastoma models","authors":"Kai Nishimura ,&nbsp;Kazuki Miura ,&nbsp;Hiroki Tanaka ,&nbsp;Minoru Suzuki ,&nbsp;Hiroyuki Nakamura","doi":"10.1016/j.apradiso.2025.111833","DOIUrl":"10.1016/j.apradiso.2025.111833","url":null,"abstract":"<div><div>Boron neutron capture therapy (BNCT) has emerged as a promising treatment for cancer, utilizing the interaction between thermal neutrons and boron-10 to selectively target and destroy cancer cells. This study evaluates the efficacy of BNCT using 4-borono-L-phenylalanine (BPA) in two different systems: reactor-based BNCT at Kyoto University Reactor (KUR) and accelerator-based BNCT at the Aomori Prefectural Quantum Science Center (QSC). The QSC cyclotron accelerator (HM-20V; Sumitomo Heavy Industries, Japan) operates a lower neutron generation capacity compared to the cyclotron accelerators (HM-30; Sumitomo Heavy Industries, Japan) used in clinical settings at Kansai BNCT Clinical Center in Osaka Medical Pharmaceutical University and Southern Tohoku Hospital. Using U87MG glioblastoma-bearing mouse models, we compared the therapeutic outcomes of both systems. This result may be partially attributed to the higher gamma-ray dose delivered by the QSC accelerator compared to KUR, which may enhance cytotoxic effects and help compensate for the lower neutron dose. Additionally, possible differences in overall neutron spectra delivered by the two different sources (KUR and QSC) used in the work described here could also have contributed to the observed outcomes.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"222 ","pages":"Article 111833"},"PeriodicalIF":1.6,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143842548","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":"Optimization of the LaBr3 detector model using differential evolution algorithms","authors":"Irina V. Prozorova ,&nbsp;Radmila R. Sabitova ,&nbsp;Sergey V. Bedenko ,&nbsp;Ruslan A. Irkimbekov ,&nbsp;Yuriy A. Popov ,&nbsp;Stanislav N. Svetachev ,&nbsp;Kuanysh K. Samarkhanov","doi":"10.1016/j.apradiso.2025.111841","DOIUrl":"10.1016/j.apradiso.2025.111841","url":null,"abstract":"<div><div>In gamma-ray spectrometry, computational detector model allows determining absolute detector efficiency for non-standard sources with varying chemical compositions in the absence of volumetric calibration standards. This study focuses on developing a computational model of a LaBr₃(Ce) 1.5\" × 1.5″ scintillation detector based on characterization data. The detector was characterized using ¹³⁷Cs and ¹⁵²Eu point calibration sources placed at various positions relative to the detector cap. Modeling was performed using the MCNP6 code based on the Monte Carlo method. The initial modeling results revealed deviations between the calculated and experimental detector responses, which required model optimization. Optimization of the detector parameters was carried out using differential evolution algorithms. To verify the optimized LaBr₃ model, studies were conducted with a volumetric KCl source. The deviations between the calculated and experimental results fell within the error limits.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"221 ","pages":"Article 111841"},"PeriodicalIF":1.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828740","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":"MRI radiomics combined with delta-radiomics model for predicting pathological complete response in locally advanced rectal cancer patients after neoadjuvant chemoradiotherapy: A multi-institutional study","authors":"Xuwei Tian ,&nbsp;Ailin Ma ,&nbsp;Zhiqiang Jia ,&nbsp;Busare Ruzeaiti ,&nbsp;Guohua Liang ,&nbsp;Hai Zeng ,&nbsp;Yuanquan Wu","doi":"10.1016/j.apradiso.2025.111842","DOIUrl":"10.1016/j.apradiso.2025.111842","url":null,"abstract":"<div><h3>Purpose</h3><div>To construct and validate a magnetic resonance imaging (MRI) radiomics combined with delta-radiomics and clinical information (C) model for predicting pathological complete response (pCR) in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (nCRT).</div></div><div><h3>Methods</h3><div>A total of 198 patients with LARC who underwent MRI before and after nCRT were retrospectively enrolled in this multi-institutional retrospective study. MRI radiomics features were extracted from pre- and post-nCRT diffusion weighted imaging (DWI) and T2-weighted imaging (T2WI) images. The least absolute shrinkage and selection operator (LASSO) and principal component analysis (PCA) algorithm were used to select the optimal predictive features. We constructed the following models, four single-modal radiomics models: DWI-post, DWI-pre, T2-post, T2-pre, two delta-radiomics models: DWI-delta, T2-delta and four multi-modal fusion models: DWI-post + DWI-pre, DWI-post + DWI-delta, DWI-post + DWI-delta + T2-delta, DWI-post + DWI-delta + T2-delta + C. The models were developed using four machine learning classifiers, including Decision Tree (DT), random forest (RF), support vector machine (SVM), and extreme gradient boosting (XGBoost).</div></div><div><h3>Results</h3><div>The multi-modal fusion model DWI-post + DWI-delta + T2-delta achieved the best performance with an area under the curve (AUC) of 0.879 for predicting pCR, which was significantly higher than that of the single-modal model DWI-post (optimal AUC = 0.824), DWI-pre (optimal AUC = 0.836) and the delta-radiomics model DWI-delta (optimal AUC = 0.841), T2-delta (optimal AUC = 0.837) in the internal validation sets. XGBoost classifier showed better prediction performance than the other classifiers in the most models. The DWI-post + DWI-pre model with DT classifier and PCA feature selection achieved the highest AUC of 0.754 and the DWI-post + DWI-delta + T2-delta + C model with SVM classifier and LASSO feature selection achieved the suboptimal AUC of 0.734 in the external validation sets.</div></div><div><h3>Conclusion</h3><div>The multi-modal fusion model significantly outperforms conventional single-modal prediction models. The model could be used as a reliable and noninvasive tool for the personalized therapy in LARC patients.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"222 ","pages":"Article 111842"},"PeriodicalIF":1.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859946","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":"Numerical dosimetry of stereotactic radiosurgery treatments in pediatric patients","authors":"Felipe B. Cruz ,&nbsp;Alessa Maschio ,&nbsp;Arthur S.B.Z. Alves ,&nbsp;William S. Santos ,&nbsp;Lucio P. Neves ,&nbsp;Ana P. Perini","doi":"10.1016/j.apradiso.2025.111840","DOIUrl":"10.1016/j.apradiso.2025.111840","url":null,"abstract":"<div><div>Brain and nervous system neoplasms account for 25 % of childhood cancer cases. In these instances, radiotherapy treatments increase survival rates, but the high radiosensitivity of pediatric patients raises concerns about the potential adverse effects of radiation. Thus, dose delivery precision becomes crucial in treatment planning, and stereotactic radiosurgeries, such as those performed with Gamma Knife equipment, are the leading-edge techniques in precision radiotherapy. This study aims to evaluate conversion coefficients for equivalent doses (CC[H_T]) for out-of-field organs using pediatric mesh-type reference computational phantoms aged 1-, 5 -, 10-, and 15-years during stereotactic radiosurgery through computational simulations with the MCNP 6.3.0 code. Higher CC[H_T] values were found for organs closer to the target organ of the treatment, such as the eyes, salivary glands, and thyroid, which received an average of 33.6 %, 6.4 %, and 2.6 % of the treatment dose, respectively. As the age of the pediatric phantom increased, CC[H_T] values in organs farther from the target region decreased due to the increase in body length. We also determined the conversion coefficients for effective doses CC[E] and observed higher CC[E] values for the computational phantom with the lowest BMI. Thus, computational simulations showed to be meaningful tool for estimating out-of-field CC[H_T] values in pediatric patients and CC[E] values, given the challenges of performing organ-level dosimetry.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"221 ","pages":"Article 111840"},"PeriodicalIF":1.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828738","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":"Beam emittance measurement of low energy H− ion beam via solenoid scan method on the injector of AB-BNCT","authors":"Chawon Park,&nbsp;Minho Kim,&nbsp;Hyunwoo Jung,&nbsp;Won Taek Hwang,&nbsp;Bong Hwan Hong","doi":"10.1016/j.apradiso.2025.111831","DOIUrl":"10.1016/j.apradiso.2025.111831","url":null,"abstract":"<div><div>Accelerator-based boron neutron capture therapy (BNCT) systems utilizing diverse accelerator technologies and neutron generation methodologies have shown promise for cancer treatment. The Korea Institute of Radiological &amp; Medical Sciences (KIRAMS) is developing a K- BNCT project with an electrostatic accelerator to produce neutrons through nuclear reactions for BNCT. A prototype 500 keV KIRAMS electrostatic tandem (KEST-500) proton accelerator and an injector test stand (ITS) have been set up to evaluate beam parameters, with a focus on measuring beam emittance while considering space charge effects. The ITS component consists of a 30 keV negative hydrogen ion (H⁻) source, a solenoid magnet, and a beam profile monitor (BPrM). The main purpose of the ITS is to obtain a full understadnding of the high-current H⁻ ion beams. Transfer matrix techniques are used to determine beam emittance at the solenoid entrance, while beam tracking simulations incorporating space charge effects provide a comprehensive analysis of beam transport. Results show the influence of beam current and energy on space charge impact and beam quality, highlighting the importance of considering space charge effects in accelerator systems.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"221 ","pages":"Article 111831"},"PeriodicalIF":1.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828739","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":"Preparation and homogeneity of a monazite sand matrix: A candidate reference material for activity concentration measurements 40K, 226Ra, 228Ra and 214Pb","authors":"Bianca Rossini Marques ,&nbsp;Rogério de Andrade Filgueiras ,&nbsp;Ademir Xavier da Silva","doi":"10.1016/j.apradiso.2025.111843","DOIUrl":"10.1016/j.apradiso.2025.111843","url":null,"abstract":"<div><div>The production of Certified Reference Materials (CRM) is an essential activity to improve and maintain a coherent measurement system worldwide. CRMs are analytical standards of high metrological reliability used for calibration, quality control, method validation and determination of the accuracy of results. This work focuses on the development of a monazite-rich sand standard according to ISO/IEC 17034. “Praia da Areia Preta”, located in Guarapari, southeastern Brazil, is known for its above-average concentration of ²³²Th. Although widely studied, there is no metrological reference (standard) for this type of sand (monazite). Homogeneity is one of the most important characteristics of CRMs, verified by the statistical method of Analysis of Variance (ANOVA) for the radionuclides in this study. Homogeneity is defined as the degree to which a property is randomly distributed throughout the material. In practice, a CRM candidate is only considered sufficiently homogeneous when the contents of its various vials do not differ sufficiently from each other to affect their intended uses, as specified in Guide 33. The mean activity concentrations and their uncertainty for each radionuclide in this study were, respectively: (33.8 ± 1.4) Bq kg⁻¹ for ⁴⁰K; (44.56 ± 0.36) Bq kg⁻¹ for ²²⁶Ra; (416.12 ± 0.68) Bq kg⁻¹ for ²²⁸Ra; and (43.96 ± 0.33) Bq kg⁻¹ for ²¹⁴Pb. The CRM candidate samples are homogeneous for the entire prepared batch. The results for Pb and Bi (²²⁶Ra) showed close values, indicating good measurement and equilibrium of the decay chain.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"222 ","pages":"Article 111843"},"PeriodicalIF":1.6,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873338","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":"Preliminary study on a new neutron spectrum measurement method for the angle and energy differential neutron field for accelerator based BNCT","authors":"S. Tamaki,&nbsp;S. Kusaka,&nbsp;F. Sato,&nbsp;I. Murata","doi":"10.1016/j.apradiso.2025.111836","DOIUrl":"10.1016/j.apradiso.2025.111836","url":null,"abstract":"<div><div>Boron neutron capture therapy (BNCT) is an effective cancer treatment that utilizes neutron irradiation; it is necessary to evaluate the characteristics of the therapeutic neutron field as accurately as possible to minimize the unwanted dose to patients. As an approach to this issue, we are currently considering a new method to measure the double-differential neutron spectrum (DDNS) in terms of both angle and energy.</div><div>In this study, a new spectrometer for this system was designed, and feasibility studies were conducted using numerical simulations. As a result, the validity of this method was confirmed at angles less than 30°. However, the evaluated spectra differed from the true spectrum at angles greater than 45°. These results imply that the current system exhibits excessive sensitivity to neutrons incident on the side surface of the spectrometer, necessitating design improvements.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"222 ","pages":"Article 111836"},"PeriodicalIF":1.6,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859945","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":"Disinfection of fungus using X-ray irradiation for the preservation of contaminated organic artifacts of traditional heritage","authors":"Gyeong-Seo Jo ,&nbsp;Yeong-Hyeok Kwak ,&nbsp;Min-Goo Park ,&nbsp;Hae-Jun Park","doi":"10.1016/j.apradiso.2025.111830","DOIUrl":"10.1016/j.apradiso.2025.111830","url":null,"abstract":"<div><div>In disaster situations such as tsunamis, floods, and typhoons, fungal contamination can significantly intensify within 48 h of submersion, rapidly spreading and damaging the value and structural integrity of organic cultural heritage artifacts. Consequently, the application of radiation-based disinfection has been increasingly studied as an effective method for prompt and reliable treatment. In most cases, the fungal species were successfully eradicated at a radiation dose of 5 kGy (gamma rays). Nevertheless, certain fungal strains demonstrated high resistance and survived even at doses ranging from 10 to 15 kGy, making disinfection more challenging. Notably, differences in threshold disinfection doses between gamma rays and electron beams (E-beams) have been reported. Therefore, this study investigated the threshold dose of X-ray radiation required to disinfect representative fungi that damage organic cultural heritage artifacts, including <em>Epicoccum nigrum</em> (high radiation resistance), <em>Cladosporium cladosporioides</em> (moderate resistance), and <em>Aspergillus niger</em> (common resistance). <em>E. nigrum</em> was effectively controlled at a dose of 12.5 kGy, while <em>C. cladosporioides</em> was controlled at 7.5 kGy and <em>A. niger</em> was controlled within the 5 kGy range. The results of this study suggest that at least 12.5 kGy of X-ray radiation should be used to preserve waterlogged traditional Korean art pieces after flooding or other water disasters.</div></div>","PeriodicalId":8096,"journal":{"name":"Applied Radiation and Isotopes","volume":"222 ","pages":"Article 111830"},"PeriodicalIF":1.6,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143854804","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}