Brazilian Journal of Radiation Sciences (BJRS)
Brazilian Journal of Radiation Sciences - BJRS ISSN 2319-0612 Una forma de impactar la cultura de seguridad y protección radiológica es establecer procesos de comunicación adecuados entre todos los actores involucrados en las aplicaciones de las radiaciones y en la protección radiológica. En este contexto, la BJRS como revista de acceso abierto, mantenida por la Sociedad Brasileña de Protección Radiológica - SBPR, sociedad asociada de la Asociación Internacional de Protección Radiológica (IRPA), tiene como objetivo difundir artículos científicos sobre las principales disciplinas de las ciencias de la radiación, entre ellas: • Efectos biológicos y en la salud de la radiación, • Protección radiológica de pacientes, trabajadores y miembros del público, • Mediciones de Radiación y Dosimetría, • Recomendaciones y Normas Internacionales, • Protección del ambiente, • Educación y entrenamiento, • Tecnología y Desarrollo, • Comunicación con la Sociedad, • Compromiso y Participación de las Partes Interesadas, • Cultura de Seguridad y Percepción de Riesgo, • Preparación y respuesta ante emergencias, • Gestión de Residuos Radiactivos, • Transporte Seguro de Materiales Radiactivos, • Seguridad Nuclear, Salvaguardias y Seguridad de los Materiales Radiactivos, • Derecho Nuclear, • Tecnología de Reactores Nucleares: nuevos conceptos, • Ciclo del Combustible Nuclear.
Sociedade Brasileira de Proteção Radiológica
Licencia: los artículos de BJRS tienen una licencia internacional Creative Commons Attribution 4.0, que permite el uso, el intercambio, la adaptación, la distribución y la reproducción en cualquier medio o formato, siempre que se otorgue el crédito correspondiente al autor o autores originales y a la fuente, proporcione un enlace a la licencia Creative Commons e indique si se realizaron cambios. Las imágenes u otros materiales de terceros en el artículo están incluidos en la licencia Creative Commons del artículo, a menos que se indique lo contrario en una línea de crédito al material. Si el material no está incluido en la licencia Creative Commons del artículo y su uso previsto no está permitido por la regulación legal o excede el uso permitido, el autor deberá obtener el permiso directamente del titular de los derechos de autor. Para ver una copia de esta licencia, visite http://creativecommons.org/licenses/by/4.0/
Calibration Of The Short Irradiation Facility For k0 - NAA Implementation At The IEA-R1 Reactor
The short irradiation facility of the IEA-R1 nuclear research reactor at IPEN, São Paulo, Brazil, has been used for short irradiation of samples for the purpose of determining the concentration of elements of these samples through the use of the instrumental neutron activation analysis technique. With the aim of implementing the k0-NAA method at the Neutron Activation Analysis Laboratory (LAN), the reactor parameters a and f were obtained using the bare triple method. In this method, a set of three neutron flux monitors were irradiated without Cd-cover. The efficiency curve of the gamma-ray spectrometer used was determined by measuring calibrated radioactive sources at the commonly used counting geometries. The results for the parameters a and f were respectively 0.0384±0.0016 and 35.67±0.26. This value of f shows that the neutrons in the irradiation position are well thermalized.The variation of these parameters was studied with time and the reproducibility was verified.
The Meeting on Nuclear Applications (ENAN) 2019
Derechos de autor 2021 Brazilian Journal of Radiation Sciences (BJRS) https://creativecommons.org/licenses/by/4.0
Fabrication and Dosimetric Evaluation of a 3D-Printed Multichannel Cylindrical Applicator Prototype for HDR Gynecological Brachytherapy
High dose-rate (HDR) brachytherapy is widely used in the treatment of gynecological cancers, but the availability of multichannel applicators remains limited in many radiotherapy centers. 3D printing has emerged as a viable alternative for manufacturing customized devices, allowing for optimized dose distribution and reduced exposure to organs at risk. This study aimed to develop and evaluate a 3D-printed multichannel cylindrical applicator for gynecological brachytherapy. The printing material was selected based on its physical properties, followed by an analysis of Hounsfield Units (HU) for different infill percentages and printing patterns. The applicator was printed using polylactic acid (PLA), and different physical and imaging tests were performed. The dose distributions obtained with the 3D-printed multichannel applicator and a single-channel were compared, with focus on target coverage and organ-at-risk exposure. Dosimetric evaluation was performed using Gafchromic® EBT4 film. The results show that the multichannel applicator enabled better dose conformity, reducing rectal exposure compared to the single-channel applicator while maintaining target coverage. Gamma analysis confirmed the accuracy of the calculated dose distribution. 3D printing seems to be a viable alternative to produce customized applicators, potentially expanding therapeutic options in gynecological brachytherapy, however, future studies should investigate the biocompatibility of the material and the clinical feasibility of the applicator.
Derechos de autor 2025 Patrícia Vieira Guimarães, Saulo Santos Fortes, Delano Valdivino Santos Batista, Rechele Grazziotin Reisner https://creativecommons.org/licenses/by/4.0
The Brazilian panorama for the calibration of Y-90 microspheres
The combination therapy approaches are gaining popularity, particularly the radiopharmaceutical therapy with external radiotherapy, immunotherapy or both. Radioembolization using Yttrium-90 Microspheres, SIR-Spheres and TheraSphere, has been used clinically in the treatment of locally advanced and unresectable Hepatic Carcinomas. According to the literature, the standardization of microspheres is not yet well established. In view of the practice of 90Y in therapies in Brazil, it is essential to develop solid standards for its measurement, in order to verify the absorbed radiation dose and its administration to the patient. This paper proposes a study of the existing standardization infrastructure for 90Y microspheres through a literature review and analysis of the measuring instruments available at the National Laboratory for Ionizing Radiation Metrology, a general analysis was made of the spectrometry and calibration methods available in Brazil, specifically at LNMRI, evaluating those suitable for use in the standardization of Yttrium microspheres. The results showed that in the period between 2000 and 2024 90Y was widely cited in treatment by radioembolization with microspheres, qualitative and quantitative evaluation of the activity quantity in PET/CT scans and its metrological characterization involving proficiency tests, study of impurities, standardization by primary and secondary methods
The Meeting on Nuclear Applications (ENAN)
Y-90 microspheres, Radioembolization, Standardization.
Derechos de autor 2025 Thamyra Cybelle Vieira dos Santos, Ms Dayana Azeredo da Conceição, Dr José Ubiratan Delgado https://creativecommons.org/licenses/by/4.0
Curva de calibración dosis–efecto automatizada para exposiciones a rayos X utilizando el ensayo de micronúcleos con bloqueo de citocinesis.
Este artículo presenta el desarrollo de una curva de calibración dosis–efecto para exposiciones a rayos X en el rango de 0 a 4 Gy utilizando el ensayo de micronúcleos con bloqueo de citocinesis y análisis automatizado, siendo el primer esfuerzo de este tipo reportado en América Latina. Este trabajo establece un referente regional para metodologías de alta capacidad en biodosimetría citogenética, destacando su potencial para mejorar la eficiencia operativa y reducir los tiempos de respuesta en emergencias radiológicas. Métodos: Se irradiaron muestras de sangre de seis donantes sanos con rayos X en siete niveles de dosis (0–4 Gy) utilizando un acelerador lineal de 6 MV calibrado. Se incluyeron dos muestras ciegas (1.5 y 3 Gy) para validación. El ensayo CBMN se realizó siguiendo los protocolos del OIEA; las láminas teñidas con DAPI se analizaron utilizando un microscopio automatizado AxioImager.Z2 integrado con el sistema Metafer4 de MetaSystems y el software clasificador MNScoreX. Para el ajuste del modelo se empleó una regresión binomial negativa (NB1), que considera la sobredispersión en la frecuencia de micronúcleos (MN). Resultados: El análisis automatizado de linfocitos binucleados mostró un aumento dependiente de la dosis en la frecuencia de MN. El modelo ajustado presentó una relación lineal–cuadrática: Y = 0.0545 + 0.0448·D + 0.0145·D², con todos los coeficientes estadísticamente significativos (p < 0.001). Las estimaciones de dosis para las muestras ciegas (1.5 y 3 Gy) coincidieron con las dosis reales dentro de los intervalos de confianza del 95%, y todos los puntajes z fueron < |3|. Conclusiones: La curva dosis respuesta sigue una función lineal–cuadrática, permitió una estimación precisa de las dosis en las muestras incógnitas, cumpliendo con los criterios de validación. Estos resultados destacan el valor de combinar microscopía automatizada con modelos estadísticos robustos para lograr evaluaciones de dosis confiables, especialmente como métodos de alto rendimiento y situaciones de emergencia radiológica.
Derechos de autor 2025 Fabio Andrés Chaves-Campos, Fernando Ortíz-Morales, Anthony Cordero-Ramírez, Julián Alonso Gómez-Castro, Jorge Ernesto González-Mesa https://creativecommons.org/licenses/by/4.0
The EDXRF Analysis to Monitor Iron Deficiency Anemia
Iron Deficiency Anemia is a significant global issue, particularly affecting pregnant women and young children. Traditional methods of diagnosing iron-deficiency anemia generally require extensive and costly laboratory procedures. This study explores the feasibility of using portable Energy Dispersive X-ray Fluorescence (EDXRF) technology for assessing iron concentration in whole blood samples from donors diagnosed with iron deficiency anemia. The results indicated a marked decrease in iron levels in the blood samples from patients with anemia compared to the control group. The EDXRF technique demonstrated several advantages, including simplicity in sample collection, rapid measurement time, and low cost. This method is particularly promising for use in situations where biological material is limited, such as in pediatric practices for newborns. The study concludes that portable EDXRF technology is an effective and efficient tool for diagnosing iron deficiency anemia, potentially improving diagnostic accessibility and outcomes.
Derechos de autor 2025 Maria Paula de Oliveira Goes, Cibele Bugno Zamboni, Maria Gabriela Miquelino Benedito, Maria Regina Andrade Azevedo https://creativecommons.org/licenses/by/4.0
Determination of the total retention capacity of 99Mo in anionic extracting agent
The Nuclear Metrology Laboratory (LMN) at IPEN-CNEN/SP is developing a research project aimed at studying analytical techniques for determining radioactive impurities, emitting alpha and beta particles. This project started with the determination of impurities present in 99Mo, which is used to obtain the radiopharmaceutical 99mTc by means of radiochemical separation in the 99Mo/99mTc generator. The study of the anionic extracting agent Strata X-A widely used in quality analysis, was realized by means a breakthrough curve in order to validate its total exchange capacity for Mo. The breaking point was determined at (2.75 +/- 0.14) mL, showing that just one 0.5 g Strata X-A cartridge is sufficient to retain 1.0 mL of a (Na2MoO4+ 99Mo) solution in concentration of 2.42 g L- 1.
Derechos de autor 2025 Ione Makiko Yamazaki, Denise Simoes Moreira, Mauro da Silva Dias, José Antonio Seneda, Marina Fallone Koskinas https://creativecommons.org/licenses/by/4.0
Monte Carlo simulation of a 6 MV Varian Trilogy clinical linear accelerator using Geant4 for small-field dosimetry analysis
In recent decades, radiotherapy has advanced significantly due to the emergence of advanced clinical linear accelerators, enabling safer and faster treatments with reduced side effects. In this study, we present a Monte Carlo simulation of a 6 MV Varian Trilogy clinical linear accelerator using the Geant4 toolkit to analyze dosimetric parameters, with a focus on small photon fields. The simulation models phase-space files generated at key beam-modification stages. Validation was performed by comparing simulated depth dose curves (PDD) and dose profiles with experimental measurements for the 6 MV photon beam, employing the gamma index (3%/3 mm criteria) to quantify the degree of agreement in the PDDs. The results agreed within a 2% difference, with over 95% of points passing the gamma analysis for a 10 x 10 cm² field. The developed framework allows for the calculation of correction factors for small-field dosimetry, addressing challenges such as lateral electronic disequilibrium in high-energy 6 MV beams, and comparing them with established values in the literature. These capabilities are particularly important for measurements of small fields used in advanced radiotherapy techniques, including Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiotherapy (SBRT), where high precision in dose deposition is essential. Overall, this work establishes a robust and flexible Geant4-based platform for simulating clinical linear accelerators, contributing to the development of more accurate dosimetric protocols for high-energy photon therapy in small fields. Preliminary observations suggest notable output factor discrepancies in small photon fields (<3x3 cm2), indicating the potential need for detector-specific correction factors. Ongoing analysis aims to confirm these trends.
Derechos de autor 2025 Andre Luiz de Carvalho Ribeiro, Alex Cristóvão Holanda de Oliveira, Leonardo Peres da Silva, Eduardo De Paiva https://creativecommons.org/licenses/by/4.0
Evaluation of Nuclear Material Balance by Statistical Analysis of the Material Unaccounted For (MUF)
Evaluating the nuclear material balance is an essential tool that can be used to assess the validity of the operator’s declarations of existing quantities of nuclear material from a facility, with an effect on safeguards agreements, where applicable. In summary, evaluating the nuclear material balance and associated safeguards activities enables the national regulatory authority to identify variations that may indicate deviations. A specific strategy used to detect potential deviations from assessing the material balance is known as "diversion into MUF", where MUF refers to the parameter Material Unaccounted For. It represents the difference between the book inventory and the ending physical inventory at the end of the material balance period. This evaluation is conducted through statistical analysis of the standard deviation of the MUF (σMUF) parameter, using an anonymous Brazilian facility as a case study. The ultimate goal is to implement this analysis within Brazil's control and accounting system, known as e-Gamma. This will enable the system to automatically perform such analyses for all facilities nationwide during each accounting period. This statistical study can be a powerful predictor of diversion, utilizing the σMUF parameter as a valuable resource. It is possible to suggest implementing this evaluation in control and accounting systems to increase efficiency in identifying and resolving discrepancies and anomalies, which is of fundamental importance in improving the reliability of a control system within the national scenario. Considering the international scenario, a country that increases its capacity to verify the accounting of nuclear material under its custody will tend to occupy a position of autonomy among its peers.
Derechos de autor 2025 Larissa R. P. Xavier, Luiz Antônio Mello, José Carlos C. Amorim, Jakler Nichele, Edson Ramos Andrade https://creativecommons.org/licenses/by/4.0
Avaliação da Lixiviação de Radionuclídeos e Exposição Externa em Materiais de Construção Contendo Resíduos NORM
A produção de dióxido de titânio no Brasil gera aproximadamente 30.000 toneladas de resíduos anualmente, conhecido como resíduo de minério não reagido (UOW), que atualmente são descartados em aterros industriais. Este resíduo é enriquecido com radionuclídeos naturais da série de decaimento de urânio e tório e é classificado como Material Radioativo de Ocorrência Natural (NORM). A reutilização de resíduos NORM em materiais de construção só é permitida se as concentrações de atividade dos radionuclídeos no produto final não representarem qualquer risco adicional de exposição para os indivíduos. A exposição à radiação de tais materiais pode ser classificada como externa - devido à irradiação gama direta - ou interna - resultante da inalação de radônio (222Rn) e seus produtos de decaimento de curta duração. Em um estudo anterior, os autores avaliaram a exposição indoor associada à incorporação de até 23% de UOW em cimento e blocos intertravados. Este estudo avaliou a viabilidade do uso desses materiais em aplicações externas, com ênfase particular no potencial de lixiviação de radionuclídeos e exposição radiológica externa. Blocos de cimento e intertravados contendo proporções variadas de rejeito de minério não reagido (0%, 3,5% e 23%) foram submetidos ao intemperismo por 60 dias. As concentrações de atividade de 238U, 226Ra, 210Pb, 232Th, 228Ra, e 40K no lixiviado foram medidas por espectrometria gama e espectrofotometria. Não foi observado aumento significativo nas concentrações de radionuclídeos no lixiviado de blocos contendo 3,5% e 23% de UOW em comparação com aqueles sem nenhum resíduo. A exposição à radiação gama permaneceu consistentemente abaixo de 0,1 mSv, e nenhuma mudança significativa foi detectada nas concentrações de radônio nas proximidades do experimento. Os resultados indicam que a incorporação de até 23% de UOW em blocos de cimento e de intertravados é segura e está em conformidade com os limites regulatórios relacionados à contaminação das águas subterrâneas e à exposição humana ao usar esses materiais em ambiente ao ar livre.
Derechos de autor 2025 Barbara Paci Mazzilli, Fenanda Yuri Muta, Lara Vitória Santos Couto, Antonio Luis Silva Costa, Vilmar Pedreira Oliveira, André Luis Batista Cabral https://creativecommons.org/licenses/by/4.0
Development of a semi-analytical nodal methodology for one-dimensional eigenvalue problems based on multigroup neutron transport theory using the discrete ordinate formulation
A semi-analytical nodal methodology is described in this paper for obtaining the numerical solution of eigenvalue problems based on neutron transport theory, in slab geometry, with isotropic scattering, using the discrete ordinates and multigroup energy formulation. This new approach applies a quadratic polynomial approximation only to the fission term in the transport equation, which justifies the method being classified as semi-analytical. The numerical solution is obtained through two interconnected iterative processes: the outer iterative process, which uses the power method to obtain successive estimates for the fission source and the effective multiplication factor (<!-- [if gte msEquation 12]><m:oMath><m:sSub><m:sSubPr><m:ctrlPr></m:ctrlPr></m:sSubPr><m:e><m:r>k</m:r></m:e><m:sub><m:r>eff</m:r></m:sub></m:sSub></m:oMath><![endif]--> <span style="font-size: 11.0pt; line-height: 107%; font-family: 'Calibri',sans-serif; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 'Times New Roman'; mso-fareast-theme-font: minor-fareast; mso-hansi-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-theme-font: minor-bidi; position: relative; top: 4.0pt; mso-text-raise: -4.0pt; mso-ansi-language: PT-BR; mso-fareast-language: PT-BR; mso-bidi-language: AR-SA;"> ), and the internal iterative process, which aims to obtain successive estimates of the angular neutron fluxes emerging from the homogeneous regions throughout the spatial domain. Once the eigenvalues are calculated, for each outer power iteration, the angular fluxes of neutrons emerging at the node faces and in the sweeping direction of the internal iterative process are estimated. These are incoming fluxes at the faces of adjacent nodes, which ensures the continuity of the numerical solution. Computational algorithms were implemented in MATLAB. Numerical results for a typical benchmark problem considering an ADS, c.f., Accelerator-Driven Subcritical Reactor, type model are provided to illustrate the accuracy of the converged numerical solutions in coarse-mesh calculations. Although the method is not free from spatial truncation error, the results for the benchmark problem were considered satisfactory with one node per region, and refining the spatial domain did not result in a high computational cost in terms of response time, with results approaching those of analytical solutions.
Meeting on Nuclear Reactor Physics and Thermal Hydraulics (ENFIR)
Semana Nacional de la Ingeniería Nuclear y Energética y de las Ciencias Radiológicas (SENCER)
Neutron transport equation, Multigroup energy formulation, Nodal methodology
Derechos de autor 2025 Natália Rocha Pinheiro, Francisco Bruno Souza Oliveira, Hermes Alves Filho https://creativecommons.org/licenses/by/4.0
Ginkgo biloba Extract: A Preliminary Study on Its Radiomitigative Potential Using the Conventional Dicentric Chromosome Assay
Radioprotectors and radiomitigators can be substances of natural or synthetic origin that, once administered to the human body, are capable of preventing, protecting against, or reducing damage caused by radiation. This study aimed to assess the radiomitigating potential of Ginkgo biloba extract by examining the frequency of dicentric chromosomes in irradiated human lymphocytes. Blood samples were obtained from a healthy volunteer. One sample was left in the laboratory as a control, and the others were irradiated in a 60Co source at a dose of 2 Gy and incubated in test concentrations of Ginkgo biloba extract (0.025 and 0.05 μg/ml) according to a standard protocol. Complete metaphases were analyzed, and the frequencies of alterations were statistically evaluated to verify the radiomitigating potential of Ginkgo biloba extract. The ANOVA and Tukey tests revealed a statistically significant difference between the groups treated and untreated with Ginkgo biloba exposed to 2 Gy of radiation (p < 0.05), indicating that both concentrations tested were able to reduce the damage. In this in vitro study, Ginkgo biloba extract was able to reduce the frequency of dicentric chromosomes in irradiated human lymphocytes, with a concentration of 0.025 μg/ml standing out.
International Joint Conference Radio (RADIO)
Derechos de autor 2025 Julio Cesar Gomes da Silva, CAIO C. V. B. G, MENDES M. E., LOPES I. M. S. S., MELO A. M. M. A, LIMA F. F. https://creativecommons.org/licenses/by/4.0
Optimization of Flight Parameters for Gamma Radiation Detection and Mapping Using Drones
The application of drones in radiometric surveys has emerged as a promising solution, particularly for mapping radiation in areas that are difficult to access. This approach enables the creation of detailed distribution maps. However, the accuracy of the results is strongly influenced by the chosen flight strategy. This study explores how different flight parameters, such as speed and grid spacing, impact the quality of gamma radiation mapping, aiming to optimize the trade-off between measurement precision and operational efficiency, such as flight time and mapping coverage. To achieve this, two experimental flights were conducted using a drone equipped with a Geiger-Müller detector, with a Cs-137 source serving as a reference. The methodology involved continuous radiation measurements during flight, with data collected at predetermined points arranged in a structured grid, via GPS coordinates. This setup facilitated the development of a three-dimensional representation of the gamma dose distribution. By comparing the results of both flights, each configured with distinct operational settings, it was possible to evaluate the impact of flight parameters on the effectiveness of radiometric detection of dose rate distribution using drones. The results suggest that dose rate mapping tends to achieve higher resolution when lower flight speeds are adopted and when data collection points are more densely distributed across the surveyed area.
Derechos de autor 2025 Felipe Mamed, Alessandra Vaz, Ary Machado, Jonathan Oliveira, Leandro Silva, Paulo Barreto, Paulo Iack, Paulo Silveira, Rodrigo Curzio, Rodrigo Souza, Wallace Vallory https://creativecommons.org/licenses/by/4.0
Image quality and dose reduction in cardiac interventional procedures: application of an optimization strategy with typical dose value analysis
This study aimed to evaluate the impact of dose‑optimization strategies on radiation exposure during cardiac catheterization and angioplasty procedures. The investigation was carried out at a high‑complexity referral center using retrospective data, clinical‑protocol adjustments, and image‑quality assessments with dedicated simulators. Implemented measures included reducing the cine dose per frame and enabling post‑processing filters, resulting in reductions of up to 39 % in reference‑point kerma and 25 % in noise intensity under low‑dose conditions. In total, 714 procedures performed over five semesters were analyzed. Diagnostic reference levels (DRLs) were determined and compared with data from national and international literature. A statistically significant reduction in DAP (16.3 %) and Kₐ,r (12.8 %) was observed for catheterization procedures (p < 0.05). Although angioplasty procedures showed a similar trend, case variability limited statistical significance. The results demonstrate the effectiveness of technical interventions and continuous monitoring in lowering exposure levels, without compromising diagnostic image quality.
Brazilian Congress on Metrology of Ionizing Radiation (CBMRI)
International Radiation Protection Association (IRPA)
II Simpósio Internacional sobre Protección Radiologica, Cusco (SIPR)
IX Congresso de Proteção Contra Radiações da Comunidade dos Países de Língua Portuguesa (PCR-CPLP)
Derechos de autor 2025 Murilo Felisberto Morais de Assunção, Emerson Nobuyuki Itikawa, Jonas Oliveira da Silva, Guilherme Custódio Cândido Silva https://creativecommons.org/licenses/by/4.0
In vivo monitoring in radiological or nuclear emergencies: a program for intercomparison of detection efficiency in NaI(Tl) portable detectors
In vivo internal monitoring is a laboratory technique used to assess and quantify the incorporation of radionuclides in the human body. Demand for such services may increase significantly in a radiological or nuclear emergency. In addition to dedicated laboratories, researchers have proposed the calibration of portable gamma radiation detectors to carry out a rapid screening of exposed individuals and assess internal dosimetry. Several international intercomparison exercises have been conducted to evaluate the performance of detectors specifically designed for internal monitoring, including, more recently, NaI(Tl) portable detectors. However, these experimental intercomparison exercises have included the transport of radioactive sources between participating institutions. The aim of this study is to propose a simple methodology for determining a reference value for the NaI(Tl) detector efficiency at 662 keV (137Cs), supporting future exercise efforts. This work employed NaI(Tl) scintillator detectors and a torso phantom. It was possible to determine an optimized measurement geometry through simulation using the MCNPX mathematical code, especially regarding the distances, and to estimate efficiency values with defined acceptance intervals for the proposed intercomparison exercise. However, additional experiments are needed to define these intervals more precisely. Complementarily, the minimum detectable effective doses were approximately 60 µSv and 38 µSv for the NaI(Tl) 2’’×2’’ and 3’’×1.5’’ detectors, respectively.
Derechos de autor 2025 MSc. Alexandre Barbosa Soares, Dr. José Ubiratan Delgado, Dr. Alfredo Lopes Ferreira Filho, Gabriel Flintz Fraga Marques https://creativecommons.org/licenses/by/4.0
Legislation and Regulations Regarding the Use of Ionizing Radiation in Phytotherapeutics in Brazil: A Documentary Analysis
This study aimed to conduct a documentary analysis of federal legislation and regulations in Brazil regarding the irradiation of phytotherapeutic products. The research was carried out between April and June 2024 through a review of official documents, including regulations, resolutions, constitutional amendments, and decrees published between 1983 and 2018. Although the analysis revealed the existence of specific norms and resolutions related to food irradiation, no direct regulation concerning the use of ionizing radiation in phytotherapeutics was identified in Brazil. National legislation addresses the use of ionizing radiation in food, particularly for radio-sterilization, with emphasis on RDC No. 21/2001, which may be indirectly applicable to medicinal plants. Normative Instruction No. 44/2014 provides the most relevant guidelines regarding the application of ionizing radiation in pharmaceuticals. In contrast, international legislation—such as that from the FDA (USA) and FSSAI (India)—explicitly regulates the radio-sterilization of medicinal herbs and plants. The documentary analysis highlights the need for the expansion, regulation, and harmonization of Brazilian standards and protocols to ensure the safe application of ionizing radiation in phytotherapeutics.
Derechos de autor 2025 Diniz, E. C., Neto, L. S. M., Silva, M. M., Amaral, A., Magnata, S. S. L. P., Araújo, L. A,, Netto, A. M., Silva, E. B. https://creativecommons.org/licenses/by/4.0
Use of Lymphoscintigraphy Images in Nuclear Medicine to Obtain the Distribution of 99mTc Photons in Computational Exposure Models
This study aims to create a source catalog for Lower Limb Lymphoscintigraphy (LLL) examinations in Nuclear Medicine, using real lymphoscintigraphy images from adult male patients. The DIP (Digital Image Processing) software, developed by the Research Group on Computational Dosimetry and Embedded Systems (GPDC&SE), was used to adjust the anteroposterior (AP) and posteroanterior (PA) medical images to the frontal section of the anthropomorphic phantom MASH_sup (Male Adult meSH in supine position). The images were summed line by line, generating a .SGI file, which was processed by the Monte Carlo software to produce the source catalog stored in the file MSUPLC_TC99m.txt. This file contains information for each slice, including the slice number, the area of the source points, and the value of the associated cumulative distribution function (CDF). As a result, a catalog based on real clinical data was successfully generated, which enables the replacement of generic internal sources in the Computational Exposure Models of the GPDC&SE. This makes it possible to simulate LLL examinations more realistically. In the future, this methodology may be extended to female patients, different phantoms, and other scintigraphic procedures. This work represents an advancement in computational dosimetry and personalized nuclear medicine, as it enables simulations that more accurately reflect patient-specific anatomical and physiological characteristics.
Derechos de autor 2025 Jorge Alexandre Gomes Lins, José Wilson Vieira, Fernando Roberto de Andrade Lima, Whoody Alem Wanderley Araripe Farias , Victor Hugo Farias Ferreira da Silva; João Mário da Silva; Ferdinand de Jesus Lopes Filho, Jefferson Melo Gonçalves Pena, Larissa Cristina Silva dos Santos https://creativecommons.org/licenses/by/4.0
Detección de Radiación Cósmica a Bajas Dosis: Revisión Integradora de Metodologías Biodosimétricas con Propuesta de Índice de Evaluación Aeroespacial
La radiación cósmica galáctica (GCR, por sus siglas en inglés) es el principal riesgo en los vuelos espaciales de larga duración cuando se considera el daño biológico. Por lo tanto, es necesario controlar la dosis absorbida y la biodosimetría se considerará una herramienta importante especialmente en escenarios donde la dosimetría física no funciona. Esta revisión integradora trata de encontrar, analizar y comparar diferentes técnicas biodosimétricas capaces de registrar bajas dosis de radiación ionizante (≤ 0,1 Gy) bajo simulación de ambientes espaciales con respecto a su aplicabilidad operacional. Se introduce el Índice de Rendimiento Biodosimétrico Aeroespacial para integrar los principales parámetros del análisis. Todos los resultados provienen de artículos originales en inglés disponibles en acceso abierto publicados entre 2019 y 2024 según un diagrama de flujo PRISMA 2020 encontrado en las bases de datos Scopus y PubMed y solo ocho estudios se consideraron elegibles para la inclusión después de realizar un cribado primario con la aplicación Rayyan. Los principales enfoques biodosimétricos reconocidos en la investigación son citogenéticos, moleculares y metabólicos. El tiempo de análisis en las metodologías fue de entre 2 y 70 horas, la viabilidad de la muestra de 1 día a 2 años, y la sensibilidad tan baja como 0.05 Gy para la dosis mínima detectable en algunos métodos. El ensayo metabólico de levadura mostró una buena aplicabilidad al combinar una alta sensibilidad con un análisis rápido y una viabilidad prolongada. Sin embargo, la ausencia de estudios que combinaran la radiación espacial con la microgravedad constituyó un inconveniente importante. Si bien muchas metodologías muestran capacidades de detección a niveles de dosis muy bajos, pocas de ellas cumplen los requisitos técnicos y operacionales cuando se consideran conjuntamente para misiones espaciales prolongadas, por lo que es un desafío para el desarrollo de métodos híbridos pero más robustos.
Derechos de autor 2025 Paulo Sérgio de Abreu Junior, Ricardo Felipe Soares, Thaís Soares Costa, Felipe L. Frigi, Liana Kalczuk, Priscila Correia Fernandes, Claudio Antonio Federico https://creativecommons.org/licenses/by/4.0
Understanding and enhancing nuclear safety culture in nuclear power plants through a quantitative system dynamics model
This study presents a quantitative system dynamics model developed to understand and enhance nuclear safety culture and operational performance in nuclear power plants. The model employs causal loop diagrams and stock-and-flow diagrams, created using Vensim PLE+ software, to capture and simulate the complex interactions that define safety culture dynamics. Recognizing the fundamental role of organizational culture in maintaining nuclear safety, the model incorporates key elements such as leadership, risk perception, continuous improvement, internal communication, and the commitment of management and personnel. Through an extensive literature review and expert consultations, the research integrates critical variables into the model, grounded in frameworks from the International Atomic Energy Agency (IAEA) and the World Association of Nuclear Operators (WANO). Simulating a decade of safety culture management dynamics, the model reveals the impact of management strategies, demonstrating the effectiveness of continuous improvement initiatives and proactive leadership in enhancing safety outcomes. Stress tests conducted under extreme scenarios validated the model's robustness, reaffirming its applicability in safeguarding safety culture under intensified production pressures. The findings provide actionable insights for nuclear safety professionals and decision-makers, promoting environments that support safety-focused practices. This model serves as a comprehensive tool to advance safety culture in nuclear operations, offering valuable perspectives for both theoretical discourse and practical nuclear safety management.
causal loop diagram and stock-and-flow diagrams
Derechos de autor 2025 Santiago Gregorio Acuña, Marcelo Oscár Gim´enez, Mariela Grinberg, Ochuko Felix Orikpete, Warren Farr https://creativecommons.org/licenses/by/4.0
Tissue Reactions (Deterministic Effects) in Diagnostic and Interventional Radiology: An Integrative Review of Recent Literature
Ninety-eight percent of the global average individual dose delivered by artificial sources of ionizing radiation results from their use in medical applications, especially for diagnostic and interventional purposes. Although the benefits of radiation in medicine are widely recognized, exposure to this agent can cause harmful effects on the health of exposed individuals. Radiation applications for diagnostic purposes are generally associated with low doses, but interventional procedures may involve much higher doses. In the 2000s and 2010s, several publications described tissue reactions in patients and professionals exposed during interventional radiological procedures. This work aimed to review the literature on the most recent reports (last decade) on the occurrence of tissue reactions after diagnostic or interventional radiological procedures. The PubMed search tool was used to search and select publications on the topic. Although 826 articles were initially selected, only 5 presented relevant content for this review. The low number of articles in the final selection may be a result of the methodology we used or an actual reduction in the number of individuals presenting these effects in more recent years, due to the growing concerns about radiological protection in these practices. Among the articles analyzed, there were reports of skin lesions, as well as thinning or hair loss in patients exposed to doses (cumulative air kerma at the reference point) above 3.5 Gy. However, these reactions are rare and do not appear in most patients, even among those who received higher doses. An increased frequency of lens opacities (cataracts) has also been reported in occupationally exposed professionals. An adequate assessment of the occurrence of these effects is essential to try to understand their causes and minimize the frequency or consequences of their occurrence. Carrying out research like this can help with this task.
Derechos de autor 2025 Laisa Neves, Lucía Canevaro Lucía Viviana Canevaro, Ana Dovales Ana Cristina Murta Dovales https://creativecommons.org/licenses/by/4.0
Realidad de los exámenes radiológicos con pacientes con limitaciones físicas.
El artículo analiza los problemas enfrentados en la práctica clínica y hospitalaria diaria en Brasil, donde no existen protocolos de examen ni bibliografías que los profesionales puedan utilizar como base para la realización de exámenes radiológicos en pacientes con limitaciones de movimiento y condiciones clínicas, como paraplejía y cuadriplejía. El objetivo de este estudio fue elaborar un pequeño libro sobre adaptación del posicionamiento radiológico para pacientes con movilidad reducida. Este material puede mejorar y optimizar los servicios que se brindan en el área, brindando una base literaria a los profesionales y una mayor seguridad radiológica y del paciente al realizar exámenes de radiología. La metodología utilizada involucró revisiones bibliográficas nacionales, visitas técnicas y seguimiento hospitalario, además de discusiones con profesionales especializados en el área de radiología, de modo que se pudiera consolidar una base más concreta y específica sobre los contenidos estudiados. A partir de estos datos, fue posible formalizar un pequeño libro simplificado, en portugués, al que se accede a través de un Código QR, con algunas adaptaciones para la posición de exámenes radiológicos para pacientes con limitaciones físicas o movilidad reducida.El pequeño libro contiene una estructura didáctica de rápida consulta para orientar mejor a los profesionales a la hora de realizar examenes. Contiene una portada, una presentación, un resumen, una introducción, un resumen de exámenes convencionales, la adaptación de los exámenes, la conclusión y finalmente las referencias. Al concluir el estudio, se destaca la importancia de ampliar la investigación encaminada a adaptar los exámenes radiológicos a pacientes con limitaciones físicas o movilidad reducida. Estas adaptaciones apuntan no sólo al bien del paciente, sino también a la salud, la protección radiológica y la seguridad ergonómica de los profesionales, evitando lesiones durante el examen o su repetición.
Adaptaciones de las exploraciones radiológicas para pacientes con movilidad reducida
Pequeño libro para pacientes con limitaciones físicas
Adaptações de exames radiológicos para pacientes com mobilidade reduzida
Adaptations des examens radiologiques pour les patients à mobilité réduite
Adaptations of radiological examinations for patients with reduced mobility
Derechos de autor 2025 Dra. Kátia Elisa Prus Pinho , Dra. Rita Zanlorensi Visneck Costa , Roberta Aumann, Dr. João Henrique Hamann https://creativecommons.org/licenses/by/4.0
Common onion extract (Allium cepa): radioprotective or radiosensitizing?
Currently, ionizing radiation has been used on a large scale in different areas of knowledge. However, despite the existence of several radioprotection regulations for workers, patients and members of the public, these are not sufficient to completely limit the possible harmful effects of ionizing radiation. For this reason, there is currently an interest in finding radiomodifying substances with radioprotective or radiomitigating activity. It is reported that approximately half of all cancer patients will require radiotherapy. Therefore, as a means of radioprotection, the use of radioprotective compounds is essential to preserve healthy cells from radiation-induced damage. Among these agents, the literature highlights natural compounds and extracts, one of which is Allium cepa, commonly known as "onion"—a plant with medicinal potential, as well as antitumoral and antioxidant properties. However, no studies have reported the application of onion extract as an antioxidant and radioprotective agent in mammalian cells. Thus, it is necessary to confirm the antioxidant and radioprotective capabilities of A. cepa extract in human lymphocytes, particularly for planned exposures to ionizing radiation. Accordingly, the aqueous extract of A. cepa bulbs was subjected to cell viability testing (MTT assay) and antioxidant capacity evaluation (ABTS and DPPH assays). Subsequently, in the presence of the extract, the micronucleus assay was performed in lymphocytes exposed to three absorbed radiation doses (ranging from 0.5 to 4 Gy). The results demonstrated that, depending on the radiation dose and extract concentration, A. cepa extract influences the formation of micronuclei. At the dose of 0.5 Gy, no statistically significant difference was observed between irradiated groups treated or not treated with the extract. At 2 Gy, an increase in micronucleus frequency was observed in the presence of the extract, whereas at 4 Gy, the opposite effect was noted. Our findings suggest that A. cepa extract is a compound with potential applications in the field of health-related radiation exposure, exhibiting dual behavior depending on its concentration and the radiation dose. These results pave the way for further investigations, involving new extract concentrations, different absorbed radiation doses, and individual variability.
Derechos de autor 2025 Dra. Raquel Cordeiro de Oliveira, Evelin Mirelle Lima Araújo, Dr. Osana Diniz Ferreira, Dra. Suy Ferreira Hwang, Dra. Ana Maria Mendonça Albuquerque de Melo, Dra. Mariana Esposito Mendes, Dr. Thiago Henrique Napoleão, Dra. Fabiana Farias de Lima https://creativecommons.org/licenses/by/4.0
Analysis of the Relationship Between Absorbed Dose and Its Effect on Plant Materials: A Literature Review
Gamma radiation has been widely explored as a physical elicitor capable of modifying plant metabolism. Its influence on the biosynthesis of secondary metabolites, which play key roles in defense, adaptation, and therapeutic action, has gained increasing interest in phytochemical and pharmacological research. This study aimed to systematically review the effects of gamma radiation on plant-derived secondary metabolites, highlighting dose-response relationships and potential biotechnological applications. A literature review was conducted using PubMed, SciELO, and BVS databases, focusing on studies published between 2019 and 2024. The search strategy included descriptors such as "gamma radiation," "secondary metabolites," and "plant materials." After applying eligibility criteria, 23 studies were selected. The studies revealed that gamma irradiation influences a wide range of secondary metabolites, including phenolics, flavonoids, terpenes, alkaloids, and saponins. Most results indicate that doses (5–100 Gy) tend to enhance the synthesis of bioactive compounds with antioxidant, antimicrobial, and anticancer properties. However, higher doses often lead to inhibitory or toxic effects. The response varied significantly across plant species and compound classes. Gamma irradiation presents great potential to optimize the production of high-value phytochemicals for therapeutic use. Nevertheless, the absence of standardized dose-response profiles and the limited understanding of molecular mechanisms highlight the need for further multidisciplinary research to ensure the safe and effective application of this technology in phytopharmaceutical development.
Derechos de autor 2025 Mario Mardone da Silva, Ewerton Clementino Diniz, Luiz da Silva Maia Neto, Liderlanio de Almeida Araújo, Simey de Souza Leão Pereira Magnata, Ademir de Jesus Amaral, Andre Maciel Netto, Edvane Borges da Silva https://creativecommons.org/licenses/by/4.0
Two-dimensional radiometric map of environmental radiation levels in a nuclear medicine service
Nuclear Medicine in Brazil has shown significant growth, with approximately 2 million procedures performed annually across 436 facilities. Ensuring that radiation exposure remains within safe limits is critical to protect patients and staff, making radiometric surveys an essential part of safety protocols. This study investigated the distribution of radiation in a nuclear medicine service in Florianópolis, Santa Catarina, using biweekly measurements collected between 2021 and 2023. A total of 2,000 samples were gathered at 40 points using a Geiger-Müller detector. The data were analyzed and mapped onto the facility’s floor plan using Paint and Excel software to generate a radiometric map. The results identified areas with elevated radiation levels and notable regional differences. The highest exposure rates were found primarily in the radiopharmacy—where radioactive materials are handled, stored, and prepared—and in radiopharmaceutical administration rooms. This radiometric map proved effective in guiding radiological protection measures and highlights the importance of continuous radiation monitoring in clinical nuclear medicine environments.
Derechos de autor 2025 Maria Eduarda Santos, Tatiane Sabriela Camozzato, Lucas Faconi Camargo https://creativecommons.org/licenses/by/4.0
Isotopic Characterization of Cumaru Essential Oil (Dipteryx odorata) for Quality and Authenticity Validation
Cumaru oil (Dipteryx odorata) has chemical properties that make it a sought-after input in the cosmetics, perfumery, alternative medicine and food industries. The appreciation of these essential oils, as well as other native plants, not only reinforces Brazil's position as a leader in the production and export of natural products, but also strengthens its identity on the international scene, promoting sustainability and environmental preservation. For the analysis of carbon-13 (δ¹³C), oxygen-18 (δ¹⁸O) and deuterium (δD) of the essential oil extracted from Cumaru seeds, isotope ratio mass spectrometry (IRMS) was used to determine the authenticity and quality of Cumaru oil. The results obtained allowed validating the methodology used both in the analysis and in the extraction of the essential oil, which used solvents such as ethanol and ethyl acetate, and demonstrated its ability to distinguish genuine products from fraud.
Derechos de autor 2025 Sarah Andresa Bonfim, Hervé Casabianca, Arno Heeren Oliveira https://creativecommons.org/licenses/by/4.0
Effective social participation in radiation protection: a necessary approach to indoor radon programs in Brazil
Effective social involvement in nuclear science and radiation protection remains a challenge, particularly in managing natural radiation exposure, such as radon gas – the largest contributor to human exposure from natural sources. This paper addresses the first Brazilian attempt to actively engage the public in a 6-month indoor radon monitoring campaign in Poços de Caldas, a region with high natural radioactivity. The study aimed to raise awareness and foster voluntary participation through a communication campaign, incorporating educational content, strategic messaging, and both virtual and in-person engagement. Despite a modest voluntary participation rate of 17%, the study found strong commitment among participants and demonstrated the effectiveness of local partnerships, digital tools, and community-driven efforts. The findings underscore the importance of tailored communication strategies and collaborative engagement to overcome barriers in public health initiatives, suggesting a need for culturally appropriate approaches to radon risk management in Brazil. Future work should focus on refining engagement strategies and assessing long-term impacts to ensure sustainable public participation in radon exposure control.
Latin-American Congress on Solid State Dosimetry and Radiation Measurements (LASSD)
Derechos de autor 2025 Danila Carrijo da Silva Dias, Wanilson Luiz Silva, Nivaldo Carlos da Silva, Paloma França Machado, Adriano Mota Ferreira https://creativecommons.org/licenses/by/4.0
Determinación de la concentración de actividad de radón (²²²Rn) en el Instituto de Protección y Dosimetría de Radiación, Río de Janeiro, Brasil.
El radón es un elemento radiactivo natural responsable de aproximadamente el 40% de la dosis anual proveniente de fuentes naturales de radiación. Según el UNSCEAR, es considerado la segunda causa principal de cáncer de pulmón. Por estas razones, es importante determinar la concentración de radón en entornos construidos. El objetivo de este estudio fue cuantificar la concentración de radón en las instalaciones del Instituto de Protección y Dosimetría de Radiación (IRD/CNEN). Las concentraciones de radón se midieron utilizando detectores de trazas nucleares de estado sólido CR-39, los cuales fueron expuestos durante 90 días en 20 edificios del Instituto, incluyendo salas, oficinas, baños y laboratorios. Los procedimientos de laboratorio se llevaron a cabo en el Laboratorio de Radón de la División de Radioprotección Ambiental y Ocupacional (DIRAD) del IRD/CNEN. Las incertidumbres estadísticas fueron proporcionadas por el software del fabricante del equipo, y los cálculos de dosis efectiva siguieron estrictamente las referencias bibliográficas apropiadas. La concentración promedio de radón encontrada fue de 86.4 Bq/m³, con un rango de 6.5 Bq/m³ a 285.4 Bq/m³, lo que demuestra el cumplimiento de las normativas nacionales. En cuanto a la dosis efectiva anual máxima, para una jornada laboral de 5 horas, los valores oscilaron entre 0.13 mSv/año y 1.33 mSv/año. Para una jornada laboral de 8 horas, los valores variaron entre 0.21 mSv/año y 2.14 mSv/año. A partir de las concentraciones obtenidas, fue posible verificar si las instalaciones del Instituto cumplen con los requisitos de la norma CNEN NN 3.01, así como calcular la dosis efectiva anual máxima para dos escenarios: jornadas laborales de 5 y 8 horas.
Derechos de autor 2025 Lucas Rezende, Dr. Paulo Roberto Rocha Ferreira, Dr. Fernando Carlos Araujo Ribeiro https://creativecommons.org/licenses/by/4.0
Determination of temporal correction factors for a survey meter detector dedicated to radioprotection in radiology
Radiometric surveying is essential for assessing radiation levels in facilities that use ionizing radiation, ensuring that individual exposures remain within the dose limits established by current regulations. Ionization chambers (ICs) are crucial tools in this evaluation, and understanding their operational limitations—particularly the effects of temporal dependence—is key to ensuring accurate measurements. This study aimed to verify the temporal dependence of the Fluke Victoreen IC (349 cm³, model 451B-RYR) by analyzing the ambient dose equivalent rate H*(10) over short exposure intervals in its two operational modes: Integrated (Mode A) and Rate (Mode B). Measurements were conducted using N60, N80, and N100 radiation qualities for narrow X-ray beams defined by ISO 4037-1:2019 and characterized at the Laboratory of Radiological Sciences (LCR). The results revealed temporal dependence for times shorter than 0.8 s for N60 and N80, and shorter than 1.5 s for N100 in both operational modes. Correction factors were calculated to adjust the H*(10) values, reducing uncertainties and enabling the definition of cutoff times for each radiometric quality and chamber mode. Mode A exhibited shorter cutoff times for N60 and N100 (0.3 s and 0.4 s, respectively), whereas Mode B proved more suitable for N80 (0.2 s). The highest combined relative uncertainties before stabilization were observed as follows: for N60, 26% in Mode A and 50% in Mode B (both at 0.1 s); for N80, 31% in Mode A and 17% in Mode B (both at 0.5 s); and for N100, 49% in Mode A (0.2 s) and 15% in Mode B (0.6 s). The study concludes that the application of correction factors and cutoff times improves the precision of H*(10) measurements at short exposure intervals, contributing to more reliable radiometric surveys in radiological protection contexts.
Derechos de autor 2025 Ellen Vilarinho da Silva, Vitoria de Lima Ribeiro Baptista, Leonardo de Castro Pacífico, Luis Alexandre Gonçalves Magalhães https://creativecommons.org/licenses/by/4.0
Primary standardization of Radionuclide 123I
Short half-life radionuclides are essential for Nuclear Medicine. These radionuclides are usually linked to a more complex molecular or cellular structure with pharmacological characteristics. This set is called “radiopharmaceutical” and have been applied for the diagnosis and therapy of diseases. The use of radiopharmaceuticals involves exposure to ionizing radiation, which, although carefully controlled, poses potential health risks to patients and healthcare professionals. To minimize these risks and maintain the benefits of its use, the radiopharmaceutical dose must be administered to patients with high accuracy and precision, this places on National Metrology Institutes new requirements for improvement for primary standardization of these short half-life radionuclides, so that the standards used to calibrate the activity meters in hospitals and nuclear medicine clinics have the greatest possible precision. Iodine-123 is currently used for several applications in radiodiagnosis, the main being in pathologies and tumors in the thyroid. In this work is presented the primary standardization of 123I performed by 4παβ(LS)-γ(NaI(Tl)) live timed anticoincidence counting and no significant radionuclidic impurities have been detected by high resolution gamma ray spectrometry. With this work, LMNRI/IRD prepared for the key comparison of the BIPM K4 series using the SIRTI instrument.
Derechos de autor 2025 Regio dos Santos Gomes, Dr. Carlos José da Silva, Dr. José Ubiratan Delgado, Monica Aguiar Leobino da Silva, R.L. da Silva, Johnny de Almeida Rangel, Dr. Luis Alberto Pereira Dias, Alfredo Lopes Ferreira Filho, Octavio Trindade Filho https://creativecommons.org/licenses/by/4.0
Construction Process with Monte Carlo of a Lead-Moderated ²⁴¹Am-Be System to Simulate the Neutron Spectrum of ²⁵²Cf
Over the years, as the use of the radionuclide ²⁵²Cf has expanded across various fields, its availability has decreased, and its cost has risen exponentially, making it the second most expensive material in the world, after antimatter. In contrast, the ²⁴¹Am-Be source is highly accessible, significantly cheaper, and has a long half-life. By employing absorber and moderator materials, neutron fields can be modified. This study presents the Monte Carlo simulation process for developing a lead-based system capable of producing a ²⁵²Cf-like neutron field from a moderated ²⁴¹Am-Be source. To match the 2.13 MeV energy of ²⁵²Cf, a spherical lead geometry with a radius of 12.56 cm was selected. The simulations achieved an average neutron energy of 2.13 ± 0.11 MeV, with conversion coefficients H*(10) and Hp(10;0) differing by only 4–6% from the reference ²⁵²Cf values. The low-cost lead moderator system suits calibration procedures and routine irradiation in neutron metrology laboratories.
Derechos de autor 2025 Angela Souza Gonçalves, Lunia Coelho de Almeida de Lima, Antônio Carlos Ferreira, Marcelo Marques Martins, Walsan Wagner Pereira https://creativecommons.org/licenses/by/4.0
A new method for voxelizing mesh phantoms through cross-sectional images
Exposure Computational Models (ECMs) utilize algorithms for ionizing radiation sources and Monte Carlo (MC) codes to simulate radiation transport, its interaction with matter, and to assess the energy deposited in volumes of interest (VOIs) represented by a phantom. The GDN (Numerical Dosimetry Research Group) (CRCN-NE) and the Computational Dosimetry and Embedded Systems Research Group (IFPE) have been developing techniques and software to create anthropomorphic Boundary Representation (BREP) phantoms, which are typically constructed using polygonal meshes due to their better anatomical representation of organs and tissues. To couple BREP phantoms with MC codes, GDN developed a method that converts polygonal meshes into voxels. This process is carried out using the in-house software DIP (Digital Image Processing), which converts mesh.obj files into voxels.sgi (Interactive Graphics Simulations). In this study, a new voxelization technique is presented, utilizing coronal images generated from a mesh phantom using the Blender application and two other tools: DIP (an in-house software) and PHAntoms Manufacturing. Essentially, the method involves using a plane to section the volume containing the phantom in the anteroposterior direction, saving an image of each slice. The total number of images generated is adjusted to reproduce a phantom height of 176 cm, targeting cubic voxels with edge lengths of 0.12 cm, resulting in 272 images. The produced images represent a collection of segmented VOIs with unique identifiers stacked in the DIP, creating an SGI file. The result of this voxelization was compared to the previous GDN method for dosimetric analyses of ionizing radiation.
Derechos de autor 2025 Raniele Costa de Matos dos Santos, Whoody Alem Wanderley Araripe Farias, José Wilson Vieira, Pedro Henrique Avelino de Andrade, Jefferson Melo Gonçalves Pena, Vanildo Júnior de Melo Lima, Fernando Roberto de Andrade Lima https://creativecommons.org/licenses/by/4.0