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La carta editorial enviada, trata sobre el decreto 3 que rige la protección radiológica en Chile y como este, a los ojos de esta autora que trabaja con radiaciones ionizantes, necesita ser actualizado.

Copyright of Revista de Investigación e Innovación en Ciencias de la Salud (RIICS) is the property of Fundacion Universitaria Maria Cano 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.)

Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco 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.)

Copyright of Latin-American Journal of Physics Education is the property of Latin-American Physics Education Network 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.)

Las técnicas de mutaciones inducidas se han utilizado eficazmente para obtener nueva variabilidad en las plantas de cultivo. Las mutaciones son la principal fuente de variabilidad genética y, por lo tanto, cierto control sobre su frecuencia puede considerarse una herramienta valiosa para el fitomejoramiento. Los mutágenos pueden agruparse en dos grandes categorías según su naturaleza: físicos y químicos. Las dosis deben optimizarse para aumentar las posibilidades de generar mutantes y lograr una población de plantas mutagenizadas que permita una selección exitosa de mutantes de interés. El objetivo de este estudio fue evaluar la sensibilidad de diferentes agentes mutagénicos en semillas de algodón de la variedad Guazuncho 3. Se evaluaron cuatro dosis de cada tratamiento y se registraron diferentes caracteres fenotípicos. Los mayores efectos sobre el porcentaje de germinación, el índice de velocidad de germinación, la supervivencia de las plantas y los efectos somáticos se observaron en los tratamientos con metanosulfonato de etilo (EMS) a medida que aumentaban las dosis. Se registraron efectos menores pero significativos en los tratamientos con azida sódica (SA) y no se observaron diferencias significativas en los tratamientos con rayos X y combinados (SA + rayos X). Los efectos sobre la tasa de crecimiento fueron significativos en los tratamientos químicos con R. = 0,84 para SA y R. = 0,97 para EMS. Además, se observó que los tratamientos con EMS y rayos X provocaron un mayor número de plantas fuera de tipo y manchas cloróticas de forma irregular. Los resultados de este estudio preliminar determinaron las dosis de mutágenos a utilizar en semillas de algodón Guazuncho 3, con el fin de generar una población M. para desarrollar un programa de mejoramiento de mutaciones.

Palestra realizada no Centro de Estudos do Hospital Central do Exército no 1° Curso de Atualização em Cancerologia.

Com a finalidade de se avaliarem as curvas de isodose fornecidas pelo fabricante da unidade de Cobalto 60 "Eldorado 78" n° 34, foram efetuadas medidas de dose em profundidade e em uma linha perpendicular ao raio central na profundidade de 5cm com e sem filtro em cunha para diversos tamanhos de campo. Os dados relativos à porcentagem de dose profunda obtidos experimentalmente e através das curvas de isodose fornecidas pelo fabricante foram comparados com os dados do Suplemento n° 11 do British Journal of Radiology. A comparação mostra uma boa concordância entre os dois primeiros e um desvio de até 5mm, entre os pontos 50%, em relação aos valores publicados pelo B. J. R.. Entre os perfis de feixe experimentais e os obtidos através das curvas de isodose fornecidas pelo fabricante, também foi encontrado um desvio de até 2mm na região de dose de 50%. Uma tabela de porcentagem de dose profunda foi obtida a partir dos dados experimentais.

Objective: To develop an automated co-registration system and test its performance, with and without a fiducial marker, on single-photon emission computed tomography (SPECT) images. Materials and Methods: Three SPECT/CT scans were acquired for each rotation of a Jaszczak phantom (to 0°, 5°, and 10° in relation to the bed axis), with and without a fiducial marker. Two rigid co-registration software packages--SPM12 and NMDosecoreg--were employed, and the percent root mean square error (%RMSE) was calculated in order to assess the quality of the coregistrations. Uniformity, contrast, and resolution were measured before and after co-registration. The NMDose-coreg software was employed to calculate the renal doses in 12 patients treated with 177Lu-DOTATATE, and we compared those with the values obtained with the Organ Level INternal Dose Assessment for EXponential Modeling (OLINDA/EXM) software. Results: The use of a fiducial marker had no significant effect on the quality of co-registration on SPECT images, as measured by %RMSE (p = 0.40). After co-registration, uniformity, contrast, and resolution did not differ between the images acquired with fiducial markers and those acquired without. Preliminary clinical application showed mean total processing times of 9 ± 3 min/patient for NMDose-coreg and 64 ± 10 min/patient for OLINDA/EXM, with a strong correlation between the two, despite the lower renal doses obtained with NMDose-coreg. Conclusion: The use of NMDose-coreg allows fast co-registration of SPECT images, with no loss of uniformity, contrast, or resolution. The use of a fiducial marker does not appear to increase the accuracy of co-registration on phantoms. [ABSTRACT FROM AUTHOR]

The Center for Radiation Protection and Hygiene (CPHR) is the institution in Cuba that provides dosimetric calibration services of instruments at radiationl protection, radiotherapy, diagnostic radiology and interventionism level. This practice is developed by the Secondary Standard Dosimetric Laboratory and guarantees the metrological traceability of dose magnitudes to a Primary Standard Dosimetric Laboratory. It is carried out in compliance with a strict Radiation Protection Program designed to guarantee the radiation safety of people and the environment and to obtain the Operating License established in the national regulatory framework. The radiation protection program includes the necessary provisions to ensure the radiation protection of people while working with ionizing radiation sources. The safety of the personnel is one of the key elements of the program and is based on requirements such as radiological control both individually and of the workplaces, the design of the facilities, operational and safety procedures and inventory control, among other aspects that have allowed compliance with the annual dose constraints imposed by the Regulatory Authority for this category of exposed personnel. This paper presents the experiences in the application of these requirements for more than 20 years. [ABSTRACT FROM AUTHOR]

A summary of the fundamental lines of medical equipment for Cuban public health developed by the Center for Technological Applications and Nuclear Development (CEADEN) is made. These lines are grouped in two fundamental directions: optical instrumentation and nuclear instrumentation for medical diagnosis, quality control and dosimetry. The main developments and impacts achieved in these two directions in the National Health System are exposed, as well as their perspectives for present and future developments. [ABSTRACT FROM AUTHOR]

Copyright of Momento: Revista de Física is the property of Universidad Nacional de Colombia, Departamento de Fisica 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.)

A basic element to achieve the measurement traceability is the correct implementation and dissemination of the measurement standards. In the case of dosimetry, there are internationally harmonized calibration methods; however difficulties may arise in their introduction related to the technical characteristics of the standards and the methods described in the technical documents. The use of commercially available dosimetry systems as secondary standards requires the personalized studies of their technical characteristics. The recommended methods do not always compatible with the available infrastructure and modifications are needed. The article makes a critical analysis of the implementation of the dosimetry secondary standards in the international arena based on the identified difficulties. [ABSTRACT FROM AUTHOR]

Given the lack of an internationally accepted code of practice for patient-specific quality control (PS-QA) of intensity-modulated radiation therapy (IMRT) treatments and the need to introduce this advanced modality into the clinical practice of the Radiation Therapy Service at the cedt-CIMEQ, the methodology recommended by the American Association of Physicists in Medicine Working Group 119 (AAPM TG-119) was assimilated and implemented. The procedures used for its habilitation and the results obtained are shown. It can be seen that the results obtained with the cedt-CIMEQ system for PS-QA, applied to all TG-119 test cases, fall within the confidence limits emanating from 10 reference centers. It could be concluded that, from the point of view of the reliability of the linear accelerator, the accuracy of the planning system and the precision of the PS-QA system, the cedt-CIMEQ is suitable for the introduction of IMRT in the clinic. [ABSTRACT FROM AUTHOR]

La carga vocal es definida como la cantidad de trabajo realizado por el mecanismo laríngeo a lo largo del tiempo. No se encontraron estudios de su valoración diferenciada en la sala de clases y en el espacio de simulación clínica. Es necesario diferenciar los resultados de los parámetros: frecuencia fundamental, intensidad vocal y ruido ambiental en ambos contextos para promover una perspectiva ecológica de la salud vocal de las docentes. El objetivo de esta investigación es determinar las diferencias en la carga vocal de un grupo de profesoras de tres establecimientos educacionales de la Región Metropolitana de Chile, en espacios de simulación clínica y laboral. Estudio comparativo transversal de 26 profesoras de educación preescolar y básica sin antecedentes de patologías vocales. La evaluación de los parámetros vocales se realizó a través de un dosímetro. El ruido ambiente fue evaluado por medio de un sonómetro. Los resultados arrojaron diferencias significativas de las tres variables entre la sala de clases y el espacio clínico simulado. También hubo diferencias significativas de intensidad y ruido ambiente entre niveles de enseñanza y cantidad de alumnos por sala, siendo mayor la intensidad y ruido en las salas de nivel básico, en comparación al nivel preescolar. Como conclusión existe una carga vocal mayor en la sala de clases, definida por un aumento en la frecuencia fundamental e intensidad, en comparación al espacio clínico simulado. Lo anterior podría estar determinado por el ruido ambiente. Se sugiere realizar intervención fonoaudiológica en el contexto laboral.

RESUMO Objetivo Verificar a diferença das medidas de frequência fundamental, intensidade e de dose vocal entre mulheres e homens cisgêneros, em situações de mesma demanda de voz. Métodos Trata-se de uma pesquisa observacional transversal. Participaram do Grupo 1 cinco homens cisgêneros, com idade entre 21 e 24 anos, e do Grupo 2, cinco mulheres cisgêneras, com idade entre 22 e 25 anos, todos sem queixas vocais e estudantes do curso de Fonoaudiologia. Os indivíduos foram pareados por demanda vocal, sendo que todos estavam matriculados nas mesmas disciplinas do curso de graduação. Todos os participantes se autodefiniram como cisgêneros, ou seja, identificaram-se com o sexo designado ao nascer. A coleta foi realizada de forma simultânea aos pares (um participante do G1 e um do G2), por um período contínuo de dez horas. Para a coleta de dados, utilizaram-se dois dosímetros da marca VoxLogⓇ. Para comparação das medidas entre os grupos utilizou-se o teste t de Student, com nível de confiança de 95%. Resultados Observou-se que as mulheres cisgêneras apresentaram maiores valores de frequência fundamental (p=0,001), porcentagem de fonação (p=0,037), dose cíclica (p=0,002) e dose de distância (p=0,008). A intensidade da voz de ambos os grupos foi semelhante no período avaliado. Conclusão Mulheres cisgêneras apresentam maiores valores de frequência fundamental, porcentagem de fonação, dose cíclica e dose de distância, do que homens cisgêneros. Avaliar a dose vocal entre os gêneros é importante para a melhor compreensão dos fatores etiológicos das disfonias comportamentais e para definir uma reabilitação vocal mais personalizada.

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.

Clinical Computed Tomography (CT) imaging is supported by a patient - technology - observers system. Such system involves dosimetric quantities associated with image quality descriptors, where operational factors are predictors. Knowledge of quantitative association between CT dosimetric and image quality quantities with systemic factors, provides the basis to devise scanner-specific optimization strategies. Kerma indexes were measured with a pencil ionization chamber free in air C a,100 and in phantom C pmma,x (x changes into c and p for center and periphery respectively). Polymethyl Methacrylate (PMMA) standard phantoms were used (diameters of 16 and 32 cm). Several operational factors of a Siemens Sensation 64 Cardiac were considered: estimated spectrums, tube potential F 8 (80 - 140 kV), tube current x time product F 1 (40 - 350 mAs) and total collimation at isocenter F 3 (2,7 - 19,2 mm). The water equivalent radius R w , an important factor for patient Size Specific Dose Estimators (SSDE), was estimated by taking into account the spectrums in each phantom. Average pixel noise was measured from Regions of Interest (ROIs) in water phantoms with radius of 2,5; 3; 6; 8 and 11,5 cm. A linear association was found between C pmma,p and C pmma,c . A dose reduction of C pmma,c = 2 mGy per tube rotation can be obtained from data analysis (head mode), with F 1 = 50 mAs, F 3 = 19,2 mm, resulting in average pixel noise of 20 Hounsfield Units (HU). Knowledge of noise association with C pmma,c provides a straightforward tool for quantitative optimization, considering a systemic approach, which includes patient - technology - observer factors.

Total Body Irradiation (TBI) is a radiotherapy technique that consists of irradiating homogeneously the whole patient’s body and it is characterized by an extended source to surface distances and the use of large irradiation fields. The limitations of the available input data and inherent problems with the calculation procedures make it very difficult to accurately determine the dose distributions in TBI. For these reasons, it is highly recommended to use In Vivo Dosimetry (IVD), to guarantee the quality of TBI treatments as a direct measurement of the delivered dose. An IVD QA system was implemented based on semiconductor diodes and radiochromic films. For the commissioning of the system, both detector types were calibrated independently, using as reference an ionization chamber with a valid certificate in terms of absorbed dose to water (Dw). This guarantees the traceability of the measurements. An experiment was carried out to simulate a clinical TBI procedure to a phantom. In this way, the calibration of the dosimetry system was confirmed.

From 1990 till 2011, a free health care program for children from areas affected by the Chernobyl accident was organized and implemented by the Cuban Government.. A significant number of qualified personal in medicine and science collaborated with this program. The information gathered for more than 21 years and the conclusive results obtained in the program are presented here. During this time, 26 114 patients, 84 % children, mostly from Ukraine, Russia and Belarus were treated in the mentioned program. Other aspects of the Cuban medical assistance in Ukraine and the main results obtained in the radiological impact evaluation of the accident on the children treated in Cuba are also included.

Propósito – Apresentar uma proposta sistemática de regulamentar a dosimetria das penalidades e os valores de multas aplicadas por entidades reguladoras. Metodologia/abordagem/design – A técnica foi desenvolvida por meio de três abordagens teórico-metodológicas: a primeira se versa sobre o direito penal, na busca pela adequação do tradicional sistema trifásico à realidade dos reguladores; a segunda adentra no viés do direito administrativo sancionador; e a terceira se baseia na teoria econômica do direito, o qual visa o bem-estar social. Resultados – A técnica permitiu a sistematização das atividades regulatórias coercitivas e sancionatórias, bem como se apresentou como uma importante ferramenta para fundamentar a dosimetria das penas. Implicações práticas – O método foi testado, e se apresentou adequado para os serviços de transporte rodoviário interestadual semiurbano de passageiros, os quais estão sob responsabilidade da Agência Nacional de Transportes Terrestres (ANTT). Por sua vez, destaca-se que a técnica pode ser adaptada a qualquer matéria regulatória que contemple penalidades e/ou multas. Originalidade/relevância do texto – O trabalho é relevante para auxiliar os agentes públicos atuantes em agências reguladoras ou em áreas afins, quando da elaboração ou edição de normativos coercitivos e sancionadores.

RESUMO Objetivo Analisar a interferência do uso do amplificador de voz na dose vocal de professoras não disfônicas. Método Trata-se de um estudo experimental, comparativo intrassujeitos, composto por 20 professoras do ensino fundamental da Rede Municipal de Ensino de Belo Horizonte/MG. Após o consentimento as participantes, foram solicitadas a responder o questionário de Escala de Sintomas Vocais – ESV e posteriormente participaram de dois momentos do estudo, selecionados aleatoriamente. No primeiro momento as participantes utilizaram somente o dosímetro vocal e no segundo momento utilizaram o dosímetro vocal e o amplificador de voz. As medições foram registradas pelo aparelho durante 1h40m, na sala de aula que as professoras lecionavam. O espaço entre as duas medições foi de uma semana, sendo mantidas a mesma sala, mesmo horário e mesma disciplina lecionada, em ambos os momentos. Resultados O parâmetro intensidade foi o único que apresentou diferença com o uso de amplificação de voz. Conclusão O uso da amplificação de voz durante a docência de professoras não disfônicas não interfere nos parâmetros acústicos de frequência fundamental, e nas medidas de dose vocal. A intensidade da voz é menor quando o professor faz uso de amplificação vocal.

In radiological protection, it is important to measure the entry dose to the skin as a direct dosimetric indicator or as a base data for a subsequent calculation of the effective dose or equivalent dose. Geiger Counters are particle and ionizing radiation detectors that emit different radiation sources. They are used as environmental dosimeters, measuring the equivalent dose rate in the air at critical points in exposed and unexposed areas in radiology services. This article shows the construction of a Geiger Müller counter from the use of open source technologies such as the arduino is, these systems allow the integration of different applications at very affordable costs, easy programming and assembly, the device not only allows measurement radiation dose perceived in conventional radiology areas, but also has a thermohygrometer capturing two extra fundamental variables for monitoring temperature and relative humidity of the equipment operating environment, in its configuration the prototype performs measurements remotely and in real time, without exposing the professional who performs the monitoring; With the location of the device in the right place, said measurement is transmitted to be viewed from any computer or mobile device, also through sending to viewing platforms, having the freedom to carry out continuous monitoring, storing said information to keep track strict in the management of emissions in the rooms where the different radiological equipment operates. [ABSTRACT FROM AUTHOR]

The Center for Radiation Protection and Hygiene was founded in 1985 to support the safe application of nuclear technologies in Cuba. Nowdays, the institution is considered as a national and regional reference for radiation protection , thanks to the comprehensive institutional strategy that support the solutions of the problems with priority in the country. The paper presents the overview about the main results of the center up today.

En este documento se hace referencia al radón, sus características físicas, peligrosidad y límites permitidos, causas de su presencia en aire y agua, causas de su presencia en el estado de Chihuahua, así como la manera de minimizar la concentración de este gas en una habitación. Se muestran los resultados de investigaciones realizadas en los años 2002 y 2003 en las que se determinó la concentración de radón en casas habitación en las 13 principales ciudades del estado de Chihuahua, por los métodos pasivos de electretos y latas de carbón activado. Se encontró que las ciudades de Aldama, Parral y Cuauhtémoc, con 225, 173 y 150 Bq/m3, respectivamente, excedían a los valores máximos permitidos para concentración de radón en habitación, de 148 Bq/m3. Hogares de la ciudad de Chihuahua, con un valor promedio de 136 Bq/m3 están muy cercanos al límite permitido. También se encontró que ciudades como Ciudad Juárez, Camargo, Bocoyna, Creel, Manuel Benavides, Ojinaga y Delicias, tuvieron valores promedio de concentración de radón bajos. Hacen falta mayores estudios para encontrar las causas de esta concentración de radón presente en estas ciudades analizadas. Abstract This paper reports radon, 222Rn, its physics characteristics, danger and the maximum contaminant level, its causes in air in houses of Chihuahua state, besides it is offered options for down the radon concentrations in a house. This work show researches made in the 2002 and 2003 when radon concentrations were measured in the main 13 cities of Chihuahua state using both passive methods like electret and diffusion barrier charcoal detectors. This paper reports that in some cities like Aldama, Parral and Cuauhtemoc, radon concentrations is higher than the limits. Chihuahua city had radon concentrations levels near at the limits. Also some cities like Ciudad Juarez, Camargo, Bocoyna, Creel, Manuel Benavides, Ojinaga and Delicias had radon concentrations levels lower than the limits. It is necessary more researches in order to find causes of presence in houses of radon concentrations high in those cities. Keywords: Radon, limits of radon, dosimetry, passive methods, Bequerel per cubic meter

Copyright of RGO: Revista Gaúcha de Odontologia is the property of RGO: Revista Gaucha de Odontologia 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.)

Copyright of Revista de Ciencias Médicas de Pinar del Río is the property of Editorial Ciencias Medicas 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.)

Copyright of La Medicina del Lavoro is the property of Mattioli 1885 SpA 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.)

En este trabajo de investigación se ha determinado el espectro de rayos X, para ello hemos diseñado un programa computacional mediante el cálculo iterativo, se han tomado las muestras de datos de atenuación y luego se ha trabajado un programa previamente diseñado con un lenguaje de programación, con los datos de atenuación. Para este caso se trabajó con los ltros de Aluminio y Cobre. Esta investigación nos ha permitido: 1.- Encontrar los espectros de radiación de rayos X. 2.- Diseñar un Programa que nos permita encontrar los espectros de rayos X, que debemos comparar con los espectros de rayos X determinados anteriormente por Tominaga (1981). 3.- Diseñar un Programa Visual de Dosimetría de rayos X. El resultado esperado es la obtención de los espectros de radiación y la optimización de la dosimetría de rayos X, en base al programa diseñado.

The Center for Radiation Protection and Hygiene was founded in 1985 to support the safe application of nuclear technologies in Cuba. Nowdays, the institution is considered as a national and regional reference for radiation protection, thanks to the comprehensive institutional strategy that support the solutions of the problems with priority in the country. The paper presents the overview about the main results of the center up today. [ABSTRACT FROM AUTHOR]

From 1990 till 2011, a free health care program for children from areas affected by the Chernobyl accident was organized and implemented by the Cuban Government. A significant number of qualified personal in medicine and science collaborated with this program. The information gathered for more than 21 years and the conclusive results obtained in the program are presented here. During this time, 26 114 patients, 84 % children, mostly from Ukraine, Russia and Belarus were treated in the mentioned program. Other aspects of the Cuban medical assistance in Ukraine and the main results obtained in the radiological impact evaluation of the accident on the children treated in Cuba are also included. [ABSTRACT FROM AUTHOR]

Copyright of Revista de Salud Pública is the property of Universidad Nacional de Colombia 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.)

Optimization and verification of Specific Patient Treatment Planning with unsealed 131I sources in hyperthyroidism diseases is a desirable goal from medical and radiation protection viewpoints. In order to verify the estimation of patient’s specific treatment dose and his/her related parameters, a combination of 3 different apparatus or pieces of equipment used in nuclear medicine were studied - the Iodine Probe, a Philips Forte Camera with pinhole collimators and a Mediso Nucline with HEGP for planar and SPECT techniques- by using the typical neck phantom and 131I sources simulating diagnosis and treatment procedure. The linear behavior on diagnostic and therapeutic activity range was verified, showing a linear correlation fitting factor R2 > 0,99. The differences between thyroid uptake determinations in all equipment were less than 6 % for therapeutic activities and less than 1,1 % in the diagnostic range. The combined protocol to calculate all the necessary parameters for the patient treatment dose planning using 2D or 3D approach was established and verified, avoiding wasting time with gamma cameras and with only one administration of 131I.

This paper describes the development of an instrument for radiological monitoring, identified as Gamma Alarm (GAMAL01). The instrument monitors the increment of radiation count rate and produces an alarm signal, when the count rate becomes superior to a fixed threshold value. The threshold is fixed to assure that the signal emission will start when the value of the radiation count rate may cause a non acceptable radiological exposition of the personnel, according to the radiological safety regulations existing in the country. Following the signal the personnel must be evacuated from the affected place. The instrument consists of two sections, an analogical section and a digital one.

Introdução: Programas de rastreamento mamográfico exigem o controle da qualidade dos exames e uso seguro da radiação. No Brasil, o Instituto Nacional de Câncer José Alencar Gomes da Silva (INCA) acompanhou esse processo. Objetivo: Descrever o contexto histórico do controle das doses e da qualidade da mamografia no Brasil sob a perspectivado INCA e os resultados obtidos por dois programas de qualidade de abrangência nacional. Método: Pesquisa descritiva, de abordagem mista, utilizando documentos e publicações relacionadas ao controle de qualidade em mamografia e resultados dos programas do INCA e do Colégio Brasileiro de Radiologia e Diagnóstico por Imagem (CBR) entre 2009 e 2016. Resultados: A pesquisa documental descreve as ações de controle de qualidade da mamografia desde a década de 1970 até o ano de 2012. Entre 2009 e 2016, foram realizadas 1.156 medidas de dose em 738 serviços e 2.633 avaliações da qualidade dos exames em 390 serviços. O valor médio da dose glandular média foi de 1,81 mGy por incidência, com 22,7% das avaliações acima dos valores de referência. Em relação à qualidade dos exames, 14,0% não estavam conformes quanto aos critérios clínicos de qualidade da imagem, 5,8% quanto aos critérios físicos e 16,7% quanto à classificação BI-RADS®. Conclusão: A análise documental revela marcos importantes da qualidade da mamografia nas últimas décadas. Os resultados dos programas do INCA e do CBR fornecem informações relevantes para o desenvolvimento de ações dirigidas ao controle da dose e da qualidade da imagem e dos laudos em mamografia.

Se estableció un protocolo de mutagénesis en microbulbos de ajo (Allium sativum L.) clon Boconó cultivado in vitro. Para el efecto se realizaron dos ensayos, uno de radiosensibilidad para establecer la dosimetría apropiada de radiación gamma y otro de mutagénesis para determinar el comportamiento de los materiales hasta la etapa de almacenamiento. En el primero los microbulbos fueron tratados con cuatros dosis de radiación gamma (6, 8, 10 y 12 Krad), más un control. Para establecer la dosis óptima se consideró la sobrevivencia del 50% de los microbulbos (DL50). Se empleó un diseño de bloques al azar con cinco tratamientos y 20 repeticiones por tratamiento. En el ensayo mutagénico los microbulbos fueron irradiados con 8 y 10 Krad y almacenados durante 45 días a 10 °C en condiciones de oscuridad En este caso se utilizó un diseño de bloques al azar con tres tratamientos (0, 8 y 10 Krad) y 20 repeticiones por tratamiento. En ambos ensayos, los microbulbos irradiados con 8 y 10 Krad registraron los mayores promedios para peso y diámetro, lo cual permite concluir que estas dosis son adecuadas para favorecer la producción de mutantes con características agronómicas deseables en el clon Boconó

Dentro da prática fisioterápica verifica-se a ampla utilização do ultrassom terapêutico para tratamento das diversas afecções musculoesqueléticas. O objetivo deste estudo foi avaliar o efeito da irradiação Ultrassônica de Baixa Intensidade, com diferentes regimes de pulsos e intensidade, em cultura celular de fibroblastos L929 (ATCC CCL-1 NCTC), de modo a verificar a viabilidade celular e definir parâmetros de dosimetria. Para isso, utilizou-se a aplicação de ultrassom pulsado, com frequência de 1Mhz, em cultura de células fibroblásticas, divididas em cinco grupos (controle e com intensidade instantâneas de 0,3W/cm2-10%; 0,3W/cm2 -20 %; 0,5W/cm2 -10% e US 0,5W/cm2 -20 % - 100Hz). A irradiação ocorreu com intervalos de 24, 48 e 72 horas, por dois minutos, e após 24 horas de cada irradiação foi realizado teste de MTT Brometo de [3-(4,5-dimetiltiazol)-2,5-difeniltetrazólio]. Os resultados revelaram que ao compararem-se os valores de células viáveis pelo método MTT nos cinco grupos, não foi possível encontrar diferença estatisticamente significativa em nenhum deles, nos três momentos avaliados (24, 48 e 72 horas); enquanto que, ao se realizar a análise de medida repetida nos diferentes grupos, encontrou-se diferença estatisticamente significativa apenas no grupo irradiado com ultrassom a 0,5W/ cm2com regime de pulso de 10% (p=0,003). Com base nesses resultados, conclui-se que a irradiação Ultrassônica de Baixa Intensidade em cultura celular de fibroblastos L929, somente no grupo com intensidade de 0,5W/cm2-10% obteve o crescimento numérico, com significância estatística em todos os períodos de avaliação.

Total Body Irradiation (TBI) is a radiotherapy technique that consists of irradiating homogeneously the whole patient's body and it is characterized by an extended source to surface distances and the use of large irradiation fields. The limitations of the available input data and inherent problems with the calculation procedures make it very difficult to accurately determine the dose distributions in TBI. For these reasons, it is highly recommended to use In Vivo Dosimetry (IVD), to guarantee the quality of TBI treatments as a direct measurement of the delivered dose. An IVD QA system was implemented based on semiconductor diodes and radiochromic films. For the commissioning of the system, both detector types were calibrated independently, using as reference an ionization chamber with a valid certificate in terms of absorbed dose to water (Dw). This guarantees the traceability of the measurements. An experiment was carried out to simulate a clinical TBI procedure to a phantom. In this way, the calibration of the dosimetry system was confirmed. [ABSTRACT FROM AUTHOR]

Clinical Computed Tomography (CT) imaging is supported by a patient - technology - observers system. Such system involves dosimetric quantities associated with image quality descriptors, where operational factors are predictors. Knowledge of quantitative association between CT dosimetric and image quality quantities with systemic factors, provides the basis to devise scanner-specific optimization strategies. Kerma indexes were measured with a pencil ionization chamber free in air Ca,100 and in phantom Cpmma,x (x changes into c and p for center and periphery respectively). Polymethyl Methacrylate (PMMA) standard phantoms were used (diameters of 16 and 32 cm). Several operational factors of a Siemens Sensation 64 Cardiac were considered: estimated spectrums, tube potential F8 (80 - 140 kV), tube current x time product F1 (40 - 350 mAs) and total collimation at isocenter F3 (2,7 - 19,2 mm). The water equivalent radius Rw, an important factor for patient Size Specific Dose Estimators (SSDE), was estimated by taking into account the spectrums in each phantom. Average pixel noise was measured from Regions of Interest (ROIs) in water phantoms with radius of 2,5; 3; 6; 8 and 11,5 cm. A linear association was found between Cpmma,p and Cpmma,c. A dose reduction of Cpmma,c = 2 mGy per tube rotation can be obtained from data analysis (head mode), with F1 = 50 mAs, F3 = 19,2 mm, resulting in average pixel noise of 20 Hounsfield Units (HU). Knowledge of noise association with Cpmma,c provides a straightforward tool for quantitative optimization, considering a systemic approach, which includes patient - technology - observer factors. [ABSTRACT FROM AUTHOR]

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]