15 results on '"López Díaz, Adlin"'
Search Results
2. Aporte de la corrección de dispersión por Tomografía para la estimación de actividad en estudios híbridos del tiroides con 131I.
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Machado López, Katlyn, López Díaz, Adlin, Robaina León, Yalaina, Martín Escuela, Juan Miguel, and Fernández Rodríguez, Viviana M.
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SINGLE-photon emission computed tomography , *TOMOGRAPHY , *BIAS correction (Topology) , *THYROID gland , *HYPERTHYROIDISM - Abstract
Hyperthyroidism is one of the most frequent MN treatments; however, quantification of 131I activity in thyroid using Single Photon Computer Tomography (SPECT) and combined with Computer Tomography (SPECT/CT techniques has almost no bibliographic history. This work studied the impact on 131I activity accuracy quantification of scatter corrections using CT information. Three sources of known activity were used for the calibration process (1.06 MBq 2.61 MBq and 4.66 MBq) with a typical uncertainty of 2.4 % and the classic thyroid phantom. The calibration factors and their uncertainty were calculated for each case. To analyze the accuracy of the system, a set of 11 sources (with activities between 1.37 MBq-3.92 MBq) were calculated and the uncertainty was estimated in each case. The relative discrepancies of the calculated activity versus reference were compared (p<0.05). The lowest average discrepancy resulted was 3 % (from 5 to 7 %) corresponding with any correction using CT. The uncertainties were found in the range of 9 to 11 %, being consistent with the discrepancies already found. Conclusions: The corrections of attenuation and dispersion by MC using CT information did not improve the 131I activity quantification accuracy in the geometry of classical thyroid phantom; although it is recommended to expand the range of masses of the thyroid to better represent the wide specific patient clinical situation and confirm these results. [ABSTRACT FROM AUTHOR]
- Published
- 2022
3. Niveles de referencia para diagnóstico en medicina nuclear e imagen híbrida. Revisión y actualización.
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Amador Balbona, Zayda H., López Díaz, Adlin, and Torres Aroche, Leonel A.
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SINGLE-photon emission computed tomography , *RADIATION protection , *INSTALLATION of equipment , *NUCLEAR medicine , *DIAGNOSTIC imaging , *PROFESSIONAL associations , *GOVERNMENT agencies - Abstract
The diagnostic image must be carried out with the minimum necessary exposure of the patient that allows the objective of the diagnosis to be satisfactorily achieved. For this reason, diagnostic reference levels emerge and are established as dynamic tools to help optimize radiation protection, contribute to the standardization of practices and strengthen culture of safety, without compromising the clinical purpose of each examination or process. The objective of this work is to provide an updated overview of the establishment and use of these levels for nuclear medicine and hybrid imaging. It is identified that to establish and use them properly, trained personnel and coordination and collaboration activities are required among multiple actors, including medical services, health authorities, professional organizations and regulatory bodies. The accelerated development of technology generally exceeds the change in regulations, so these levels must be updated periodically, in order to fulfil their role as a guide and spur for optimization. The worldwide expansion of hybrid technologies and their growing use are a phenomenon of the last decade, so the establishment of these levels for such technologies has not been consolidated, although countries such as the United Kingdom and Australia show solid steps in this address. Research has been carried out with phantoms and directly with patients, the latter with a more useful contribution of information. The installation of hybrid equipment in Cuba demands this study, hence its importance. [ABSTRACT FROM AUTHOR]
- Published
- 2022
4. Calidad de la imagen de tomografía computarizada versus dosis en estudios híbridos: resultados preliminares en maniquí.
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López Díaz, Adlin, del Pozo Almaguer, Armando, Machado Tejeda, Adalberto, Batista Ramó, Karla, Calderón Marín, Carlos F., and Torres Aroche, Leonel
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Background: hybrid studies produce a total radiation dose that is the result of the dose imparted by the radiopharmaceutical and that emitted by the computed tomography, therefore optimization is essential. Objective: to evaluate the relationship of the computed tomography dose with some image quality parameters in hybrid study protocols. Methods: to evaluate the image quality, the Catphan and Livermore phantom were used in 12 pre-established protocols of a Mediso single photon emission tomography equipment. The data for the dose descriptors for each study were obtained from the DICOM head. The classic image quality parameters such as noise and the MTF 50% for the Catphan phantom, and others such as the contrast-noise ratio, the average of Hounsfield numbers and their standard deviation in the regions of interest of the corresponding organs were compared, in Livermore's phantom. The relationship of these quality parameters with the dose descriptors of the different protocols was analyzed. Results: the quality-related parameters in the Catphan phantom did not show significant differences (p <0.05) between the different protocols for hybrid studies. Significant differences were found between the clinical protocols with different qualities and the standard clinical protocol, for the anthropomorphic phantom, in the standard deviation of the Hounsfield numbers and in the contrast-to-noise ratio (p <0.05). Conclusions: the study of the contrast noise ratio and the deviation of the computed tomography numbers in the regions of interest can serve as a quantitative parameter for the optimization of doses in the clinical setting.. [ABSTRACT FROM AUTHOR]
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- 2022
5. Estudio de los indicadores de dosis por tomografía computada en un sistema híbrido SPECT/CT: resultados preliminares.
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López Díaz, Adlin, del Pozo Almaguer, Armando, Machado Tejeda, Adalberto, Martín Escuela, Juan Miguel, Batista Ramó, Karla, Torres Aroche, Leonel Alberto, Calderón Marín, Carlos Fabián, and Fernández Rondón, Manuel
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SINGLE-photon emission computed tomography , *IMAGING systems , *HYBRID systems , *RADIATION doses , *NUCLEAR medicine , *COLLIMATORS - Abstract
The introduction in Cuba of imaging hybrid systems in nuclear medicine has become a challenge for medical physicist in order to guaranty the patient´s radiation safety and proper dose estimation. The aim of this study was to retrospectively evaluate the CT radiation doses for studies performed with a SPECT/CT hybrid system (SPECT/CT). A MATLAB “in house” made tool was tested and validated for this purpose. 62 patients with CT studies were manually and automatically reviewed; the tool could visualize and properly recover the patient personal information, CT protocol and dose related data from the DICOM header in the SPECT/CT study file. The CT volume dose index (CTDIvol) parameter was used for calculating the CT dose-length product (DPL) and the effective doses (E). The CT radiation dose preliminary results were on the range of those reported by others authors for the typical studies, demonstrating the efficacy of the tool developed and the CT dose assessment method. [ABSTRACT FROM AUTHOR]
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- 2022
6. Cirugía radioguiada del cáncer de mama en Cuba: presente y futuro.
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López Díaz, Adlin, Miguel Martín, Juan, Rodríguez Paleo, Lester, Loyz Fernández, Jorge L., González Espinosa, Claudia, González, Joaquín J., Guerrero Cancio, Mayka, Roque Díaz, Reinaldo, Dranguet Palacios, Orlando, Pérez González, Francisco, Caridad Rubio, María, García Rodríguez, Berta, and Varela Corona, Consuelo
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MINIMALLY invasive procedures , *OPERATIVE surgery , *ADULT education workshops , *MEDICAL research , *BREAST , *CANCER patients , *AXILLA , *BREAST implants , *CEREBRAL arteriovenous malformations - Abstract
This work summarizes the results of the national project Comprehensive quality improvement in the diagnosis and treatment of patients with cancer and other diseases, incorporating and strengthening radioguided surgery techniques. This project had the objective of raising the quality in the diagnosis and treatment of patients with cancer and other diseases, by introducing, expanding and optimizing the clinical use of radioguided surgery in Cuba. First, the technique was started in the “Hermanos Ameijeiras” hospitals, the National Institute of Oncology and Radiobiology and the Center for Medical Surgical Research, with the protocolized follow-up and the analysis of the clinical impact, the national guidelines were drawn up and the accreditation proceeded. of courses and workshops for the training of human resources, guaranteeing sustainability and extension to other hospitals. As main results, in February 2020, 570 breasts had been operated with this technique, with a rate between 65-70 % of unnecessary axillary emptyings avoided, noting the improvement in staging and diagnostic precision the decrease in surgical time per patient in 30 %, lower costs of surgery, fewer associated complications and shorter hospital stays due to minimally invasive surgery and a significant improvement in the quality of life of patients. Conclusions: radioguided surgery was introduced and consolidated as an oncological surgical optimization method. [ABSTRACT FROM AUTHOR]
- Published
- 2022
7. Análisis de riesgo en la terapia paciente específica del hipertiroidismo en Cuba.
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Amador Balbona, Zayda Haydée, Torres Valle, Antonio, and López Díaz, Adlin
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FAILURE mode & effects analysis ,NUCLEAR models ,NUCLEAR medicine ,MEDICAL specialties & specialists ,SERVICE design - Abstract
Copyright of Revista Habanera de Ciencias Médicas is the property of Universidad de Ciencias Medicas de La Habana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
8. Predictores clínicos y de imagen funcional con 99tecnecio - sestamibi para diferenciar el grado de malignidad en gliomas cerebrales
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León Castellón, Roberto, Gómez Viera, Nelson, Salva Camaño, Silvia, López Díaz, Adlin, Castro Jiménez, Mayte, and Martín Escuela, Juan Miguel
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Single-Photon Emission-Computed Tomography ,Brain Neoplasms ,Tomografía Computarizada de Emisión de Fotón Único ,Technetium ,MeSH) ,Neoplasias Encefálicas ,Tecnecio ,(DeCS) - Abstract
RESUMEN INTRODUCCIÓN: Los gliomas son los tumores primarios más frecuentes del Sistema Nervioso Central. La tomografia de Emisión de Fotón Único (SPECT) es una técnica de imagen funcional que nos permite acceder a información molecular y diferenciar los gliomas entre sí y de otras entidades nosológicas.. De ello depende la estrategia terapéutica a emplear y el pronóstico en estos pacientes. OBJETIVO: determinar la utilidad de las características clínicas de los pacientes al ingreso y de la SPECT cerebral con 99Tc-MIBI para diferenciar el grado de malignidad de los gliomas cerebrales. PACIENTES Y MÉTODOS: estudio observacional, descriptivo y prospectivo realizado en pacientes del Hospital Clínico Quirúrgico "Hermanos Ameijeiras" y del Hospital Universitario "General Calixto García" durante el período mayo 2012 - febrero 2015. La muestra quedó constituida por 102 pacientes con diagnóstico confirmado de glioma cerebral y con estudio de SPECT Cerebral con 99mTc-MIBI. RESULTADOS: Los principales síntomas y signos, así como el índice de Karnofsky al ingreso no mostraron diferencias significativas respecto al grado de malignidad de los gliomas cerebrales estudiados. Los pacientes con gliomas de alto grado se caracterizaron por una elevación de todos los índices tumorales, así como de la cuantificación de la actividad, concentración volumétrica del 99mTc-MIBI para ambas fases, aunque más marcado para la fase tardía e índice de retención. El Indice tumor corteza contralateral en fase tardía mostró una sensibilidad, especificidad, valor predictivo positivo y negativo de 98,9%, 94,0%, 63,0% y 99,0% respectivamente para diferenciar el grado de malignidad de los gliomas cerebrales. La razón fase tardía/fase temprana del índice tumor/corteza contralateral mostró valores de sensibilidad de 94,1%, especificidad de 98,5%, valor predictivo positivo de 98,7% y valor predictivo negativo de 98,8%. El índice de retención del radiofármaco tuvo una sen-sibidad de 99%, especificidad de 89%, y valores predictivos positivo y negativo de 95% y 99% respectivamente. CONCLUSIÓN: La combinación de: Indice tumor corteza contralateral en fase tardía, razón fase tardía/fase temprana del ÍNDICE tumor/corteza contralateral y el índice de retención del radiofármaco son los parámetros más útiles para predecir el grado de malignidad de los gliomas cerebrales utilizando la SPECT con 99mTc-MIBI. SUMMARY INTRODUCTION: Gliomas are the most common primary tumors of the Central Nervous System. Single Photon Emission Tomography (SPECT) is a functional imaging technique that allows us to access molecular information and differentiate gliomas from each other and from other entities. It depends on the therapeutic strategy to be used and the prognosis in these patients. OBJECTIVE: To determine the utility of the clinical characteristics of patients on admission and of the brain SPECT with 99mTc-MIBI to differentiate the degree of malignancy of brain gliomas. Patients and methods: An observational, descriptive and prospective study carried out in patients from "Hermanos Ameijeiras" Hospital and "Calixto García" University Hospital during the period May 2012 to February 2015. The sample consisted of 102 patients with confirmed diagnosis of brain glioma and with study of Brain SPECT with 99mTc-MIBI. RESULTS: The main symptoms and signs, as well as the Karnofsky index on admission did not show significant differences regarding the degree of malignancy of the brain gliomas studied. Patients with high-grade gliomas were characterized by an elevation of all tumor indices as well as quantification of activity, volumetric concentration of 99mTc-MIBI for both phases, although more marked for the late phase and retention index. Tumor / contralateral cortex index in late phase showed a sensitivity, specificity, positive and negative predictive value of 98.9%, 94.0%, 63.0%, and 99.0% respectively to differentiate the degree of malignancy of brain gliomas. Late phase / early phase ratio of the tumor / contralateral cortex index showed sensitivity values of 94.1%, specificity of 98.5%, positive predictive value of 98.7%, and negative predictive value of 98.8%. Radiopharmaceutical retention index had a sensitivity of 99%, specificity of 89%, and positive and negative predictive values of 95% and 99% respectively. CONCLUSION: The combination of: Tumor / contralateral cortex index in late phase, late phase / early phase ratio of the tumor / contralateral cortex index, and radiopharmaceutical retention index are the most useful parameters for predicting the degree of malignancy of brain gliomas using SPECT with 99mTc-MIBI.
- Published
- 2017
9. SPECT cerebral con 99Tc- MIBI para discriminar entre infiltración tumoral y absceso cerebral en casos de tomografía computarizada y resonancia magnética no concluyentes. Presentación de un caso
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León Castellón, Roberto, Cepero Llauger, Kali, Rodríguez Rodríguez, Carmen, Castro Jiménez, Mayte, Fernández Cue, Leda, López Díaz, Adlin, and Martín Escuela, Juan Miguel
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Brain abscess ,99mTc - MIBI ,SPECT cerebral 99mTc - MIBI ,Absceso cerebral ,Brain SPECT - Abstract
La diferenciación entre abscesos y metástasis cerebrales en pacientes con algún grado de inmunosupresión y con neoplasias hematológicas resulta en ocasiones difícil. Los estudios funcionales como la tomografía de emisión de fotón único (SPECT) y la tomografía por emisión de positrones (PET) son herramientas diagnósticas eficaces para este propósito. Presentamos el caso de una paciente con diagnóstico de leucemia mieloide crónica en crisis blástica a quien se le informó múltiples abscesos cerebrales; diagnóstico basado en que no existió captación de 99mTc - MIBI en SPECT cerebral y en la buena respuesta al tratamiento antimicrobiano en ocasión en que los estudios de tomografía computarizada (TC) cerebral y resonancia magnética (RM) cerebral no fueron concluyentes. Teniendo en cuenta los resultados de la SPECT se decidió postergar el esquema de quimioterapia, ya que esta podría desencadenar complicaciones probablemente fatales en la paciente. The differentiation between brain abscess and brain metastasis in patients with some grade of immune suppression and hematological neoplasm is difficult in some situations. Functional studies like Single-Photon Emission Tomography (SPECT) and Positron Emission Tomography (PET) are useful for this purpose. We present the case of a patient with diagnosis of chronic myelogenous leukemia in blast crisis that a diagnosis of brain abscess was made. The diagnosis had a base in 99mTc - MIBI brain SPECT did not show MIBI uptake and the good treatment response to antibiotics when brain CT scan and MRI were not conclusive. Attending to the SPECT result, chemotherapy was postponed because of probably fatal complications in this patient with brain abscess.
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- 2016
10. Predictores clínicos y de imagen funcional con 99tecnecio - sestamibi para diferenciar el grado de malignidad en gliomas cerebrales
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León Castellón, Roberto, primary, Gómez Viera, Nelson, additional, Salva Camaño, Silvia, additional, López Díaz, Adlin, additional, Castro Jiménez, Mayte, additional, and Martín Escuela, Juan Miguel, additional
- Published
- 2017
- Full Text
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11. La física médica en la ciudad de La Habana.
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Alfonso Laguardia, Rodolfo, López Díaz, Adlin, and Díaz Rizo, Oscar
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NUCLEAR science , *PRIVATE security services , *PHYSICISTS , *THERAPEUTICS , *NUCLEAR medicine , *RADIOTHERAPY , *RADIATION protection - Abstract
The main contributions in the applications of nuclear sciences and technologies to the diagnosis and treatment of neoplasic diseases, obtained by medical physicists from various Havana institutions are summarized. Additionally, the main activities to guarantee the training and accreditation of medical physicists for radiodiagnosis, nuclear medicine, radiotherapy and radiation protection services in Havana hospital network is presented. [ABSTRACT FROM AUTHOR]
- Published
- 2019
12. Estimación de las desviaciones volumétricas de dosis entregada vs. planificada durante el tratamiento de hipertiroidismo con 131I: resultados preliminares.
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López Díaz, Adlin, Miguel Martín, Juan, Fernández, Viviana, Pérez, Amalia, and Ramos Rodríguez, Eduardo O.
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NUCLEAR medicine , *CURVE fitting , *MAXIMA & minima , *IMAGING phantoms , *RADIATION dosimetry , *DEVIATION (Statistics) - Abstract
In 2013, the European Association of Nuclear Medicine Dosimetry Committee recommends a "Standard Operational Procedures for Hyperthyroidism Pre-Therapeutic Dosimetry" based on the assessment of the individual 131I uptake and kinetics. To estimate the 3D dose delivery deviations from prescribed dose during patient specific application of this SOP, a computer Matlab application was developed and verified. It was design to execute: radiopharmaceutical curve fitting, cumulated activity calculations, functional thyroid mass estimation, obtain the therapeutic planning activity to warranty the prescribed dose and produce the 3D planning dose map and related dosimetry parameters. 6 patients with 150-400Gy prescribed dose data planning (average 241,67Gy) were analysed using the developed application. The developed system was verify successfully using a test image phantom and 6 known pharmacokinetics data. The tridimensional thyroid volume cumulated activity and dose distributions were heterogeneous. 3D dose distribution showed standard deviations between 18.01- 27.08 % of prescribed dose. The differences between maximum and minimum dose value per voxel/ MBq were 74-129%. According to the result, between 50,2 % and 71,4 % of patient's thyroid will be treat with a dose of DP±20 % of planned dose, the rest will be overdose or sub dose. Conclusions: the 3D treatment planning dose distribution were completely no-homogenous, the significant difference observed should be study in the future more deeply in order to optimized the hyperthyroidism iodine treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2019
13. Evaluación por Monte Carlo de los métodos de corrección de dispersión con 131I empleando colimador pinhole.
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López Díaz, Adlin, Rodríguez Pérez, Sunay, Díaz García, Angelina, San Pedro, Aley Palau, and Martín Escuela, Juan Miguel
- Abstract
Scattering is quite important for image activity quantification. In order to study the scattering factors and the efficacy of 3 multiple window energy scatter correction methods during 131I thyroid studies with a pinhole collimator (5 mm hole) a Monte Carlo simulation (MC) was developed. The GAMOS MC code was used to model the gamma camera and the thyroid source geometry. First, to validate the MC gamma camera pinhole-source model, sensibility in air and water of the simulated and measured thyroid phantom geometries were compared. Next, simulations to investigate scattering and the result of triple energy (TEW), Double energy (DW) and Reduced double (RDW) energy windows correction methods were performed for different thyroid sizes and depth thicknesses. The relative discrepancies to MC real event were evaluated. The accuracy of the GAMOS MC model was verified and validated. The image's scattering contribution was significant, between 27-40 %. The discrepancies between 3 multiple window energy correction method results were significant (between 9-86 %). The Reduce Double Window methods (15 %) provide discrepancies of 9-16 %. Conclusions: For the simulated thyroid geometry with pinhole, the RDW (15 %) was the most effective. [ABSTRACT FROM AUTHOR]
- Published
- 2017
14. Protocolo para la realización de la gammagrafía de mamas con 99mTc-MIBI empleando un dispositivo de posicionamiento decúbito prono.
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Del Pozo Almaguer, Armando, Suárez Iznaga, Rodolfo, López Díaz, Adlin, and Varela Corona, Consuelo
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MEDICAL protocols , *MEDICAL needs assessment , *LYMPH nodes , *PATHOLOGY , *CANCER diagnosis , *AXILLA , *BREAST - Abstract
Breast cancer is the second most frequent neoplasm in the Cuban woman. Image techniques play a fundamental role for the diagnosis, staging and monitoring of the disease. This work had the objective of: Implement the Clinical Protocol for the scintimammography with 99mTc-MIBI for the detection of palpable tumor lesions in dense breasts, difficult mammographic assessment and suspected axillary metastatic lymph nodes employing a craft device of prone decubitus positioning. 35 patients were included with an average age of 51 years, who attended the central consultation of breast pathology at Dr. Salvador Allende Hospital. It was designed and constructed an artisanal device that made it possible to carry out the studies from an anatomical position pendant or pendulum of the breast, demonstrating its usefulness in the medical assessment of the scintimammography images. Of the studies carried out 17.1 % was positive for malignant mammary neoplastic tissue, with a specificity of 100 %. The number of unnecessary biopsies by false positive mammograms or inconclusive in lesions greater than 10 mm in diameter was decreased by 82.9 %. The clinical protocol was implemented for the scintimammography with 99mTc-MIBI for the detection of palpable tumor lesions in dense breasts, difficult mammographic assessment and suspected axillary metastatic lymph nodes employing a craft device of prone decubitus positioning. It proved to be a simple, reproducible and non-invasive test, which can facilitate and improve the diagnosis of breast cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2022
15. EDUCPRA: portal web especializado de educación y capacitación en protección radiológica de Cuba.
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Valdés Ramos, Maryzury, Manzano de Armas, José Francisco, García Lima, Omar F., González Rodríguez, Niurka, Fernández Gómez, Isis M., López Díaz, Adlin, Castro Soler, Ailza, Cárdenas Herrera, Juan, López Bejerano, Gladys M., Fornet Rodríguez, Ofelia M., and Rodríguez Rodríguez, Maidelys Rosa
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WEB portals , *WEBSITES , *CERTIFICATION , *RADIATION protection , *OCCUPATIONAL training , *STANDARDS , *GRAND strategy (Political science) - Abstract
The paper focuses on a high-priority subject nationwide: the growing need for training in radiation protection for occupationally exposed workers and the strength of having specialized web portals on this matter. The Specialized Web Portal, EDUCPRA "Cuba's Portal for Education and Training in Radiological Protection", has been developed in this context, which makes available to its users, in an easy and integrated way, access to contents, regulations, national and international standards, directories, applications and services related to the matter that allow the identification, dissemination, and promotion of the training capacities in radiation protection. The main objective of EDUCPRA is to become the technological support of the National Strategy for Education and Training in Radiological Protection. EDUCPRA allows supervising the operation of the education and training activity in Radiological Protection in Cuba, and contributing to the processes of identification of needs, certification of personnel, and competence recognition of radiation protection courses. Through EDUCPRA, the available capacities to the country can be promoted to be able to comply with the training requirements established in the national regulatory framework, and the number of personnel trained by practice and occupational category can be known, allowing the evaluation of the effectiveness of the national training program. EDUCPRÁ will give visibility to the performance indicators of the training in Radiological protection in the country. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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