Dosis de radiación por radiografías y factores asociados en neonatos de la Unidad de Recién Nacidos del Hospital Universitario San Ignacio, Bogotá, Colombia / X-ray radiation dose and associated factors in neonates from the newborn unit of Hospital Universitario San Ignacio, Bogotá, Colombia

Introducción. Las radiografías continúan usándose ampliamente, subestimando los riesgos. Esto sucede, especialmente, en las unidades de cuidado neonatal, lo que implica que los neonatos reciben una dosis de radiación ionizante mayor que los adultos. Objetivo. Cuantificar las dosis de radiación recibidas al tomar radiografías y evaluar los posibles factores asociados con el aumento de la dosis. Materiales y métodos. Se llevó a cabo un estudio observacional de 160 neonatos de la Unidad de Recién Nacidos del Hospital Universitario San Ignacio, Bogotá, Colombia. Se consideró como variable dependiente la dosis de entrada en piel por cada radiografía. Se hizo la caracterización de los pacientes, seguida de un análisis multivariado con regresión lineal múltiple para identificar factores asociados. Resultados. Se analizaron 160 pacientes y 492 radiografías en total. Entre los hallazgos más frecuentes, se encuentran: pacientes de sexo masculino (n=87; 54,4 %), nacimiento por cesárea (n=122; 76,3 %) e indicación de toma de radiografías por dificultad respiratoria (n=123; 24,9 %). El 1,8 % (n=9) de los pacientes no tenían una indicación para la toma de la radiografía. La radiografía más frecuente fue la de tórax (n=322; 65,4 %). La mayoría de las radiografías se tomaron con el equipo computarizado (n=352; 71,5 %) y no con el digital (n=140, 28,4 %). La mediana de la dosis de entrada en piel con el equipo computarizado fue de 0,112 mGy (0,022; 0,134 mGy) y, con el equipo digital, de 0,020 mGy (0,019, 0,022 mGy). Conclusiones. Se cuantificaron las dosis de radiación absorbida en neonatos, general y específica, con el equipo computarizado y el digital. Se identificaron mayores dosis con el equipo computarizado. Se reconoció la interacción entre el equipo computarizado con menores edades gestacionales corregidas como principal factor para el aumento de la dosis. Además, se reconoció la relación entre el equipo computarizado y una menor edad gestacional corregida, como principal factor para una mayor dosis.

Introduction. Radiographs are still widely used, underestimating the risks. This situation is frequent in neonatal care units, generating radiation doses than in adults. Objective. To quantify the received radiation doses when performing radiographs on neonates and the possible factors associated with higher doses. Materials and methods. We performed an observational study of 160 neonates from the newborn unit of the Hospital Universitario San Ignacio, Bogotá, Colombia. We considered the input dose of each radiograph as the dependent variable. Patients were characterized and a multivariate analysis with multiple linear regression was performed to identify associated factors. Results. We analyzed 160 newborns and 492 radiographs. The most frequent findings were male patients (n=87, 54.4%), cesarean delivery (n=122, 76.3%), and radiograph indication for respiratory distress (n=123, 24.9%). One-point eight percent of the patients (n=9) did not have radiograph indication. The most frequently taken radiograph was chest (322, 65.4%). Most radiographs were taken with a computerized equipment (n=352, 71.5%), compared to a digital one (n=140, 28.4%). The median input dose with computerized equipment was 0.112 mGy (0.022, 0.134 mGy), and with the digital equipment was 0.020 mGy (0.019, 0.022 mGy). Conclusions. The general and specific absorbed radiation doses were measured in neonates with a computerized and a digital equipment. We identified higher doses with the computerized equipment. In addition, it was recognized the correlation between computerized radiography equipment with lower corrected gestational ages as the main factor for dose increase.

Análise comparativa das doses cardíacas recebidas por pacientes com câncer de mama esquerda planejadas com duas formas alternativas de delineamento do CTV da cadeia mamária interna / Comparative analysis of heart doses received by patients with left breast cancer planned with two alternative internal mamary delineation CTVs

Propósito. Com a publicação, na última década, do resultado de grandes estudos demonstrando a correlação entre a dose de radiação recebida no coração e o aumento de eventos cardíacos adverso. Nosso estudo investiga a possibilidade de reduzir a dose cardíaca de radiação sem utilizar os protocolos ideais de inspiração profunda (DIBH). Metodologia. Analisamos os parâmetros dosimétricos referentes a 43 pacientes recebidas no departamento de radioterapia da Santa Casa de Maceió tratadas com radioterapia adjuvante em mama ou plastrão esquerdos incluindo fossa e cadeia mamária interna (MI). Todas as pacientes foram submetidas a duas tomografias e planejamentos distintos, com e sem inspiração profunda (DIBH), em um protocolo simplificado adequado para a realidade do Sistema Único de Saúde (SUS). Foram analisados os efeitos dosimétricos sobre o volume alvo, o coração, o pulmão esquerdo com o DIBH simplificado e com formas alternativas de delineamento da cadeia mamária interna. Resultados. Em nosso estudo, o protocolo de DIBH simplificado demonstrou uma redução da dose média cardíaca mesmo em pacientes incluindo radiação nodal regional ampla (692 cGy vs 502 cGy - p < 0,0001). As doses médias no ventrículo esquerdo (VE) (1222 cGy vs 857 cGy ­ p < 0,0001), na artéria coronária anterior descendente (LAD) (3739 cGy vs 3345 cGy ­ p = 0,0001) e outros parâmetros como o V25% do coração (12,4% vs 7,7% - p < 0,0001) também se mostraram reduzidas. Os delineamentos alternativos da cadeia mamária interna (MI) não produziram alterações significantes nas doses cardíacas ou pulmonares. O melhor parâmetro para predizer o benefício do DIBH foi a expansibilidade do pulmão esquerdo (r = 0,6 - p < 0,0001), sendo que os pacientes com relação entre o pulmão normal e o inspirado menor que 1,3-1,4 não obtiveram benefício significativo. Doses pulmonares também tiveram melhora estatisticamente significativa com o DIBH (média 1448 cGy vs 1294 cGy ­ p < 0,0001; V20 32,6% vs 28,2% - p <0,0001; V5 48,7% vs 45,4% - p < 0,0005), Conclusão. Nosso estudo indica que um protocolo simplificado de DIBH pode ser uma alternativa para beneficiar pacientes selecionados que necessitam reduzir a dose cárdica de radiação em tratamentos e mama esquerda e drenagens regionais em serviços de radioterapia de alta demanda e recursos limitados

Purpose. In the last decade, seminars studies demonstrated the correlation between radiation doses received in the heart with the incidence of cardiac disease, such as acute coronary events. This aroused the interest in new techniques to reduce this problem. Numerous studies have already shown that Deep Inspiration Breath Hold (DIBH) may be the best option for reducing cardiac dose. However, the vast majority of these investigations were carried out in a different scenario from the one found in our reality. Our study investigated the feasibility of reducing the cardiac dose without using an ideal DIBH protocol, which are difficult to implement in services with high demand and low economic support. Methods. The dosimetric parameters of 43 patients from the radiotherapy department of Santa Casa de Maceió were analyzed. All patients were treated with adjuvant radiotherapy to the left breast, including supraclavicular fossa and internal mammary chain (IM). The patients underwent two different CT scans and planning, with and without DIBH, in a simplified protocol suitable for the reality of tour public health system (Free Breath Hold; no respiratory training; selection of only the patients with greater benefit). The dosimetric impact on the heart, its substructures and the left lung were studied with the simplified DIBH and with alternative forms of delineation to the IM. Results. The simplified DIBH protocol demonstrated, in our study, a reduction in mean cardiac dose for patients including wide regional nodal radiation (692 cGy vs 502 cGy - p < 0.0001). The doses for the Left ventricular (1222 cGy vs 857 cGy ­ p < 0.0001), the Left anterior-descending coronary (3739 cGy vs 3345 cGy ­ p = 0.0001) and other parameters such as heart V25% (12.4% vs 7, 7% - p < 0.0001) were also reduced. The doses to the heart did not achieve statistically significant reduction with alternative delineation of the MI CTV. The best parameter predicting the benefit of DIBH was the left lung expansion (r = 0.6 - p < 0.0001), with patients with a ratio lower than 1.3-1,4 having no significant benefit. Pulmonary doses also showed a statistically significant improvement with DIBH (Dmed 1448 cGy vs 1294 cGy ­ p < 0.0001; V20 32.6% vs 28.2% - p <0.0001; V5 48.7% vs 45, 4% - p < 0.0005), but the reductions were small, as was the increase in pulmonary dose when the MI CTV is outlined to joining the supraclavicular fossa. Conclusion. Our study indicates that a simplified DIBH protocol may serve as an option to benefit selected patients with locally advanced breast cancer treated in departments with high occupation of the Linacs and low capacity for investment in new technology

Research Progress in Diagnostic Reference Levels in Interventional Radiology / 中国医学科学院学报

During interventional procedures,subjects are exposed to direct and scattered X-rays.Establishing diagnostic reference levels is an ideal way to optimize the radiation dose and reduce radiation hazard.In recent years,diagnostic reference levels in interventional radiology have been established in different countries.However,because of the too many indicators for characterizing the radiation dose,the indicators used to establish diagnostic reference levels vary in different countries.The research achievements in this field remain to be reviewed.We carried out a retrospective analysis of the definition,establishment method,application,and main factors influencing the dose difference of the diagnostic reference level,aiming to provide a basis for establishing the diagnostic reference level for interventional procedures in China.

Quality of Images Reconstructed by Deep Learning Reconstruction Algorithm for Head and Neck CT Angiography at 100 kVp / 中国医学科学院学报

Objective To evaluate the impact of deep learning reconstruction algorithm on the image quality of head and neck CT angiography (CTA) at 100 kVp. Methods CT scanning was performed at 100 kVp for the 37 patients who underwent head and neck CTA in PUMC Hospital from March to April in 2021.Four sets of images were reconstructed by three-dimensional adaptive iterative dose reduction (AIDR 3D) and advanced intelligent Clear-IQ engine (AiCE) (low,medium,and high intensity algorithms),respectively.The average CT value,standard deviation (SD),signal-to-noise ratio (SNR),and contrast-to-noise ratio (CNR) of the region of interest in the transverse section image were calculated.Furthermore,the four sets of sagittal maximum intensity projection images of the anterior cerebral artery were scored (1 point:poor,5 points:excellent). Results The SNR and CNR showed differences in the images reconstructed by AiCE (low,medium,and high intensity) and AIDR 3D (all P<0.01).The quality scores of the image reconstructed by AiCE (low,medium,and high intensity) and AIDR 3D were 4.78±0.41,4.92±0.27,4.97±0.16,and 3.92±0.27,respectively,which showed statistically significant differences (all P<0.001). Conclusion AiCE outperformed AIDR 3D in reconstructing the images of head and neck CTA at 100 kVp,being capable of improving image quality and applicable in clinical examinations.

Comparação Dosimétrica entre Técnicas de Planejamento de Radioterapia para Câncer de Mama Esquerda / Dosimetry Comparison of Radiotherapy Planning Techniques for Left Breast Cancer / Comparación Dosimétrica entre Técnicas de Planificación de Radioterapia para el Cáncer de Mama Izquierdo

Introdução: A radioterapia é utilizada no tratamento do câncer de mama. No planejamento radioterápico, há formas de desenvolver o plano de tratamento, como a radioterapia 3D conformacional (3D-CRT), a radioterapia de intensidade modulada (IMRT) e a arcoterapia volumétrica modulada (VMAT). Objetivo: Comparar as doses nos órgãos de risco e no volume-alvo de tratamento com as diferentes técnicas de planejamento: 3D-CRT, IMRT, VMAT e VMAT modificada para o tratamento do câncer de mama em um phantom antropomórfico. Método: O plano de tratamento foi realizado no sistema Eclipse™ v.15.6 da Varian a partir de imagens de tomografia computadorizada adquiridas de phantom. A dose de prescrição estabelecida foi de 45 Gy em 25 frações de 1,8 Gy/dia. Resultados: Sobre a cobertura do volume do alvo planejado (PTV), as técnicas 3D-CRT (FILTRO e field-in-field ­ FIF) demonstram cobertura inferior comparada aos planos de IMRT e VMAT. Já o plano 3D-CRT-FIF apresenta maior homogeneidade comparado ao 3D-CRT-FILTRO. Para o pulmão contralateral, os planos de 3D-CRT (FIF, FILTRO) obtiveram restrições melhores em relação aos demais planos. Sobre a exposição cardíaca, os planos 3D-CRT (FIF, FILTRO) apresentaram maiores benefícios do que as técnicas IMRT, VMAT e VMAT modificada. Conclusão: As técnicas convencionais 3D-CRT (FIF, FILTRO) apresentaram menores doses nos órgãos de risco. Contudo, as técnicas IMRT e VMAT obtiveram melhor homogeneidade e conformidade da dose distribuída no PTV ao comparar as técnicas convencionais.

Introduction: Radiotherapy is utilized to treat breast cancer. For radiotherapy planning, there are several ways to develop the treatment plan, such as 3D conformal radiotherapy (3D-CRT), intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT). Objective: To compare the doses to risk organs and treatment target volume with different planning techniques, 3D-CRT, IMRT, VMAT and modified VMAT for the treatment of breast cancer in an anthropomorphic phantom. Method: The treatment plan was performed in the Eclipse™ v.15.6 system by Varian from CT images acquired from phantom. The established prescription dose was 45 Gy in 25 fractions of 1.8Gy/day. Results: For the planning target volume (PTV) coverage, 3D-CRT techniques (FILTER and field-in-field ­ FIF) showed inferior coverage compared to IMRT and VMAT plans. The 3D-CRT-FIF plan, on the other hand, shows greater homogeneity when compared to 3D-CRT-FILTER. For the contralateral lung, the 3D-CRT plans (FIF, FILTER) have better restrictions when compared with the other plans. On cardiac exposure, the 3D-CRT (FIF, FILTER) plans showed greater benefits when compared with IMRT, VMAT and Modified VMAT techniques. Conclusion: Conventional 3D-CRT techniques (FIF, FILTER) showed lower doses in organs at risk. However, IMRT and VMAT techniques obtained better homogeneity and conformity of the dose delivered to the PTV when compared to conventional techniques

Introducción: La radioterapia se utiliza en el tratamiento del cáncer de mama. En la planificación de la radioterapia, existen formas de desarrollar el plan de tratamiento, como la radioterapia conformacional 3D (3D-CRT), la radioterapia de intensidad modulada (IMRT) y la arcoterapia volumétrica modulada (VMAT). Objetivo: Comparar las dosis en órganos de riesgo y en el volumen blanco de tratamiento con diferentes técnicas de planificación: 3D-CRT, IMRT, VMAT y VMAT modificada para el tratamiento del cáncer de mama en un fantoma antropomórfico. Método: El plan de tratamiento se realizó en el sistema Eclipse™ v.15.6 de Varian a partir de imágenes de TC adquiridas del fantoma. La dosis de prescripción establecida fue de 45 Gy en 25 fracciones de 1,8Gy/día. Resultados: En cuanto a la cobertura del volumen blanco de planificación (VBP), las técnicas 3D-CRT (filtro - FILTRO y field-in-field ­ FIF) demostraron una cobertura inferior en comparación con los planes IMRT y VMAT. El plan 3D-RCT-FIF mostró mayor homogeneidad en comparación con el 3D-RCT-FILTRO. Para el pulmón contralateral, los planes 3D-CRT (FIF, FILTER) obtuvieron mejores restricciones en comparación con los otros planes. En la exposición cardiaca, los planes 3D-CRT (FIF, FILTER) mostraron mayores beneficios en comparación con las técnicas IMRT, VMAT y VMAT modificada. Conclusión: Las técnicas convencionales de 3D-CRT (FIF, FILTER) mostraron dosis más bajas en los órganos de riesgo. Sin embargo, las técnicas IMRT y VMAT obtuvieron una mejor homogeneidad y conformidad de la dosis distribuida en el VBP en comparación con las técnicas convencionales.

Adaptive extended‑field intensity-modulated radiation therapy with simultaneously integrated boost for locally advanced cervical cancer with lymph node metastases / Philippine Journal of Obstetrics and Gynecology

@#Performing external beam radiotherapy alone without chemotherapy or brachytherapy for locally advanced cervical cancer with multiple lymph node metastases is challenging. The purpose of this case report is to present the efficacy of high‑dose adaptive extended‑field intensity‑modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) in treating locally advanced cervical cancer with multiple lymph node metastases. A 67‑year‑old woman with locally advanced squamous cell carcinoma of the uterine cervix was treated by external beam radiotherapy alone due to the refusal of chemotherapy and intracavitary brachytherapy. In order to maximize the efficacy of treatment, extended‑field radiotherapy that includes the paraaortic lymph nodes as well as an adaptive IMRT‑SIB plan, was applied. The treatment was successful, resulting in complete tumor disappearance without severe adverse events. In conclusion, high‑dose adaptive IMRT‑SIB may be an alternative treatment option for locally advanced cervical cancer with multiple lymph node metastases.

Desempeño de los Tecnólogos Médicos como Oficiales de Protección Radiológica - 2021 / Performance of Medical Technologist as Radiation Protection Officers Lima - 2021

Las radiaciones ionizantes tienen el potencial de generar efectos adversos a la salud de las personas. Para hacer un uso más seguro y eficiente de estas radiaciones, la Comisión Internacional de Protección Radiológica fundamentalmente ha implementado un sistema de protección radiológica (SPR) que se basa en tres principios: justificación, optimización y límites. A su vez, estos principios se sustentan en cuatro valores éticos (beneficencia, prudencia, justicia y dignidad). Se sabe que en Chile el profesional que esta mandatado para realizar la toma de los exámenes que utilizan radiaciones ionizantes es el/la Tecnólogo Médico en Imagenología. Por lo tanto, resulta interesante valorar el grado de conocimiento adquirido y posteriormente aplicado en torno a los valores éticos del SPR por parte de dichos profesionales. De esta manera el objetivo del este artículo de tipo Punto de Vista fue realizar una serie de reflexiones en torno a esta temática. Cuando se realiza un procedimientos médico u odontológico con radiaciones ionizantes, el/la Tecnólogo Médico en Imagenología participa esencialmente en la realización del mismo, por lo que no debería ser su responsabilidad el cautelar que se cumplan los 4 valores éticos descritos dentro del SPR. A juicio nuestro, el principio de optimización, sería el único principio o pilar del SPR donde tiene real obligación de participar, utilizando las restricciones a las exposiciones individuales y los niveles de referencia para diagnóstico para reducir las desigualdades en la distribución de las exposiciones entre los grupos expuestos. Finalmente, resulta vital investigar si en su formación de especialidad se tocan estas temáticas.

Ionizing radiation has the potential to generate adverse effects on people's health. To make safer and more efficient use of these radiations, the International Commission on Radiological Protection has fundamentally implemented a radiological protection system (RPS) based on three principles: justification, optimization and limits. In turn, these principles are based on four ethical values (beneficence, prudence, justice and dignity). It is known that in Chile the professional who is mandated to perform the exams that use ionizing radiation is the Medical Imaging Technologist. Therefore, it is interesting to assess the degree of knowledge acquired and subsequently applied around the ethical values of the RPS by these professionals. In this way, the objective of this Point of View article was to make a series of reflections on this subject. When a medical or dental procedure is performed with ionizing radiation, the Medical Imaging Technologist essentially participates in its performance, so it should not be their responsibility to ensure that the 4 ethical values described in the RPS are met. In our opinion, the principle of optimization would be the only principle or pillar of the RPS where it has a real obligation to participate, using the restrictions on individual exposures and the diagnostic reference levels to reduce inequalities in the distribution of exposures between exposed groups. Finally, it is vital to investigate whether these topics are addressed in his specialty training.

The Effects of Different Adaptive Statistical Iterative Reconstruction-V and Convolution Kernel Parameters on Auto-Segmentation Stability in CT Images / 中国医疗器械杂志

Objective The study aims to investigate the effects of different adaptive statistical iterative reconstruction-V（ ASiR-V） and convolution kernel parameters on stability of CT auto-segmentation which is based on deep learning. Method Twenty patients who have received pelvic radiotherapy were selected and different reconstruction parameters were used to establish CT images dataset. Then structures including three soft tissue organs (bladder, bowelbag, small intestine) and five bone organs (left and right femoral head, left and right femur, pelvic) were segmented automatically by deep learning neural network. Performance was evaluated by dice similarity coefficient（ DSC） and Hausdorff distance, using filter back projection(FBP) as the reference. Results Auto-segmentation of deep learning is greatly affected by ASIR-V, but less affected by convolution kernel, especially in soft tissues. Conclusion The stability of auto-segmentation is affected by parameter selection of reconstruction algorithm. In practical application, it is necessary to find a balance between image quality and segmentation quality, or improve segmentation network to enhance the stability of auto-segmentation.

Ionizing Radiation Exposure in Children with Vesicoureteral Reflux: Should We Be Alarmed? / Exposición a radiacion ionizante en niños con reflujo vesicoureteral: Debemos preocuparnos?

Objectives Ionizing radiation imaging is commonly used for diagnosis and follow up in children with vesicoureteral reflux (VUR). We aim to measure the effective dose (mSv) in patients with VUR. Methods We reviewed our electronic database of patients under 8-years-old with VUR. Primary endpoint was to calculate the effective radiation dose (ED). Absolute frequencies and percentages were reported for global qualitative variables. This study conducted a logistic regression model to calculate the odds ratio for radiation exposure. Analysis was performed using STATA version 14.0 (StataCorp LLC, College Station, TX, EEUU). Results A total of 140 patients were found, 97 were assessed for eligibility. We included 59 patients in the final analysis. Mean age was 20 ± 17.9 months, 66% were females. Most cases of VUR were bilateral (44%) and high grade (93.4%). The lowest number of studies per patient was two, with a minimum radiation of 5.7 mSv. The highest radiation was estimated at 20.7 mSv corresponding to a total of five studies. Logistic regression showed that highest grades of VUR and age of first UTI episode were associated with higher ED (OR, 1.7; 95% CI, 0.87-3.31), (OR 1.02; 95% CI 0.97-1.07) respectively. A mean ED for children with VUR was estimated of 5.5 ± 3 mSv/year. Conclusion In our study, the children with VUR were exposed to 5.5 mSv/year without counting the natural background radiation, which is alarming, and we believe should raise awareness worldwide in how we are unnecessarily diagnosing indolent VUR cases and following patients.

Objetivos La imagenología por radiación ionizante es una herramienta usada frecuentemente para el diagnóstico y seguimiento de pacientes con reflujo vesicoureteral (RVU). El objetivo del presente trabajo es calcular la dosis estimada en milisieverts (mSv) de pacientes con RVU. Métodos Se realizó una revisión retrospectiva de todos los pacientes menores de 8 años con RVU. El objetivo principal fue calcular la dosis de radiación efectiva recibida por los pacientes con base en los estudios imagenológicos realizados hasta el momento de la revisión de la base de datos. Las frecuencias y porcentajes fueron reportados para las variables cualitativas. Se realizó una regresión logística para calcular la asociación de factores de riesgo con la exposición a radiación. El análisis estadístico fue realizado con el programa STATA versión 14.0 (StataCorp LLC, College Station, TX, EEUU). Resultados Se identificaron 140 patientes, de los cuales 97 fueron evaluados para coprobar su elegibilidad. En total, 59 pacientes fueron incluidos para el análisis final. La edad promedio de los pacientes fue de 20 ± 1,.9 meses, y 66% eran mujeres. La mayoría de casos fueron bilaterales (44%) y de alto grado (93,4%). El menor número de estudios realizados por paciente fue 2, con una dosis mínima de radiación acumulada de 5,7 mSv. La máxima radiación acumulada fue de 20,7 mSv, correspondiente a un total de 5 estudios. La regresión logística demostró que altos grados de reflujo y la edad a la cual tuvieron la primera infección se asociaban con mayores dosis de radiación efectiva (razón de probabilidades [RP]: 1.7; intervalo de confianza del 95% [IC95%]: 0,87­3,31), (RP: 1,02; IC95%: 0,97­1,07), respectivamente. Estimamos una dosis efectiva de radiación de 5,5 ± 3 mSv/año en nuestra población. Conclusión Nuestro estudio demuestra que pacientes con reflujo son expuestos a un promedio de 5,5 mSv/año sin contar la radiación de base a la que se exponen todos los humanos anualmente, lo cual resulta alarmante. Esto debe generar introspección al momento de evaluar pacientes con reflujo y evitar efectos a largo y mediano plazos.

Proteomic analysis of human keratinocytes under UVA-induced stress / Análise proteômica de queratinócitos humanos sob estresse induzido por luz UVA

The solar ultraviolet (UV) radiation that reaches the Earth is composed of 95% of UVA (320 to 400 nm) and 5% of UVB (280 to 320 nm) radiation. UVB is carcinogenic, generating potentially mutagenic DNA lesions. The solar UVA radiation also causes DNA damage, but this fact does not fully account for its biological impact. UVA is absorbed by non-DNA cellular chromophores, generating reactive oxygen species such as singlet oxygen. Knowing the proteome mediates stress responses in cells, here we investigated the cellular effects of a non-cytotoxic dose of UVA radiation, equivalent to about 20 minutes of midday sun exposure, on the proteome of human keratinocytes. Using a combination of mass spectrometry-based proteomics, bioinformatics, and conventional biochemical assays, we analyzed two aspects of UVA-induced stress: spatial remodeling of the proteome in subcellular compartments 30 minutes after stress and long-term changes in protein levels and secretion (24 hours and 7 days postirradiation). In the first part of this thesis, we quantified and assigned subcellular localization for over 3000 proteins, of which about 600 potentially redistribute upon UVA exposure. Protein redistributions were accompanied by redox modulations, mitochondrial fragmentation and DNA damage. In the second part of the work, our results showed that primary human keratinocytes enter senescence upon exposure to a single dose of UVA, mounting antioxidant and inflammatory responses. Cells under UVA-induced senescence further elicit paracrine responses in neighboring premalignant HaCaT epithelial cells via inflammatory mediators. Altogether, these results reiterate the role of UVA radiation as a potent metabolic stressor in the skin

A radiação ultravioleta (UV) solar que atinge a superfície terrestre é composta por 95% de radiação UVA (320 a 400 nm) e 5% de radiação UVB (280 a 320 nm). A radiação UVB é carcinogênica e gera lesões potencialmente mutagênicas no DNA. A radiação UVA solar também gera danos no DNA, mas a genotoxicidade dessa radiação não explica inteiramente o seu impacto biológico. Atualmente, sabe-se que a radiação UVA é absorvida por cromóforos celulares, gerando espécies reativas de oxigênio, como o oxigênio singlete. Sabendo que o proteoma é um mediador de respostas ao estresse celular, nós investigamos os efeitos celulares de uma dose não-citotóxica de radiação UVA, equivalente a cerca de 20 minutos de exposição ao sol, no proteoma de queratinócitos humanos. Utilizando espectrometria de massas, bioinformática e ensaios bioquímicos convencionais, nós analisamos dois aspectos do estresse induzido por radiação UVA: o remodelamento espacial do proteoma 30 minutos depois do estresse e alterações nos níveis e na secreção de proteínas no longo prazo (24 horas e 7 dias depois da irradiação). Na primeira parte desta tese, nós quantificamos e atribuímos classificações de localização subcelular a mais de 3000 proteínas. Dentre essas proteínas, 600 tem potencialmente a sua distribuição subcelular alterada em resposta à radiação. As redistribuições subcelulares são acompanhadas de modulações redox, fragmentação mitocondrial e danos no DNA. Na segunda parte da tese, os nossos resultados mostraram que queratinócitos humanos primários entram em senescência sob exposição a uma única dose de radiação UVA, montando respostas antioxidantes e pró-inflamatórias. Células sob senescência induzida por UVA, por sua vez, desencadeiam respostas parácrinas em queratinócitos pré-tumorais (células HaCaT) por meio de mediadores inflamatórios. Em conjunto, esses resultados reiteram o papel da radiação UVA como um potente estressor metabólico em células da pele

Uma reflexão sobre o uso da tomografia computadorizada em Endodontia / Considerations on the use of computed tomography in Endodontics

Será o exame de tomografia computadorizada realmente de alto custo para o paciente, ou existe uma resistência por grande parte dos profissionais em indicá-lo? Paradigmas já foram quebrados com relação à dose de radiação. Ela é tão pequena que, em muitas universidades nos EUA, o paciente não utiliza avental de chumbo durante o exame. Isso se dá porque o exame usado para Endodontia tem algumas diferenças em relação à tomografia médica (AU).

Is the CT scan really a high cost for the patient, or is there a resistance on the part of most professionals to indicate it? Paradigms have already been broken with regard to the radiation dose. In many universities in the USA, the patient does not wear a lead apron during the exam because the dose is so small. The reason for this is that the exam used for Endodontics has some differences in relation to medical tomography (AU).

The Effects of 2100 MHz Radio Frequency Radiation on Thyroid Tissues

ABSTRACT Objective: To reveal the effect of 2100 MHz radio frequency (RF) radiation on thyroid tissues of rats in the 10 days (group E1) and 40 days (group G1) exposure groups. Methods: In this study, 30 healthy female Wistar albino rats, weighing 200−256 g each, were used. The animals were randomly divided into four groups (E1, E2, G1 and G2). Groups E2 and G2 served as the control groups. The exposure groups were exposed to 2100 MHz RF radiation emitted by a generator, simulating a 3G-mobile phone for 6 hours/day, 5 consecutive days/week, at the same time of the day (between 9 am and 3 pm), for 10 days (group E1) and 40 days (group G1). Results: Catalase and xanthine oxidase enzyme activities were compared between the groups E1 and E2; it was found that the difference was statistically significant (p < 0.05). Between the groups G1 and G2, the difference was found to be significant with respect to catalase activities. Tissue samples of the early and late groups showed no serious pathological findings in the histopathological examination. Conclusion: We believe that comprehensive, clinical and experimental studies are needed to assess the effect of the RF exposure duration and dosage of exposure on thyroid tissues.

Prediction of impacts on liver enzymes from the exposure of low-dose medical radiations through artificial intelligence algorithms

SUMMARY OBJECTIVES: This study aimed to develop artificial intelligence and machine learning-based models to predict alterations in liver enzymes from the exposure of low annual average effective doses in radiology and nuclear medicine personnel of Institute of Nuclear Medicine and Oncology Hospital. METHODS: Ninety workers from the Radiology and Nuclear Medicine departments were included. A high-capacity thermoluminescent was used for annual average effective radiation dose measurements. The liver function tests were conducted for all subjects and controls. Three supervised learning models (multilayer precentron; logistic regression; and random forest) were applied and cross-validated to predict any alteration in liver enzymes. The t-test was applied to see if subjects and controls were significantly different in liver function tests. RESULTS: The annual average effective doses were in the range of 0.07-1.15 mSv. Alanine transaminase was 50% high and aspartate transaminase was 20% high in radiation workers. There existed a significant difference (p=0.0008) in Alanine-aminotransferase between radiation-exposed and radiation-unexposed workers. Random forest model achieved 90-96.6% accuracies in Alanine-aminotransferase and Aspartate-aminotransferase predictions. The second best classifier model was the Multilayer perceptron (65.5-80% accuracies). CONCLUSION: As there is a need of regular monitoring of hepatic function in radiation-exposed people, our artificial intelligence-based predicting model random forest is proved accurate in prediagnosing alterations in liver enzymes.

Segurança, Eficácia e Protocolo de Dose de Metoprolol para Redução de Frequência Cardíaca em Pacientes Pediátricos Externos que Passaram por Angiografia Cardíaca por TC / Safety, Efficacy, and Dose Protocol of Metoprolol for Heart Rate Reduction in Pediatric Outpatients Undergoing Cardiac CT Angiography

Resumo Fundamento Qualidade de imagem e dose de radiação são otimizadas com uma frequência cardíaca (FC) lenta e estável na realização de imagens de artérias coronárias durante a angiografia cardíaca por tomografia computadorizada (CCTA, do inglês cardiac computed tomography angiography) A segurança, a eficácia e o protocolo para a redução da FC com medicamento betabloqueador ainda não foi bem descrita em uma população de pacientes pediátricos. Objetivo Oferecer um protocolo de dose de metoprolol eficiente a ser usado em pacientes pediátricos externos durante a CCTA. Métodos Realizamos uma revisão retrospectiva de todos os pacientes pediátricos externos que receberam o metoprolol durante a CCTA. As características demográficas e clínicas foram resumidas e a redução média em FC foi estimada utilizando-se um modelo de regressão linear multivariada. As imagens foram avaliadas em uma escala de 1 a 4 (1= ideal). Resultados Um total de 78 pacientes externos passaram a uma CCTA com o uso de metoprolol. A média de idade foi de 13 anos, a média de peso foi de 46 kg, e 36 pacientes (46%) eram do sexo masculino. As doses médias de metoprolol foram 1,5 (IQR 1,1; 1,8) mg/kg, e 0,4 (IQR 0,2; 0,7) mg/kg para administrações orais e intravenosas, respectivamente. O produto dose-comprimento por exame foi de 57 (IQR 30, 119) mGy*cm. A redução média da FC foi 19 (IQR 12, 26) batimentos por minuto, ou 23%. Não foram relatadas complicações ou eventos adversos. Conclusão O uso de metoprolol num cenário de pacientes pediátricos externos para redução da FC antes de uma CCTA é seguro e eficiente. Pode-se reproduzir um protocolo de dose de metoprolol quando for necessário atingir uma FC mais lenta, garantindo tempos de aquisição mais rápidos, imagens mais claras e redução na exposição à radiação nessa população. (Arq Bras Cardiol. 2021; 116(1):100-105)

Abstract Background Image quality and radiation dose are optimized with a slow, steady heart rate (HR) when imaging the coronary arteries during cardiac computed tomography angiography (CCTA). The safety, efficacy, and protocol for HR reduction with beta blocker medication is not well described in a pediatric patient population. Objective Provide a safe and efficient metoprolol dose protocol to be used in pediatric outpatients undergoing CCTA. Methods We conducted a retrospective review of all pediatric outpatients who received metoprolol during CCTA. Demographic and clinical characteristics were summarized and the average reduction in HR was estimated using a multivariate linear regression model. Images were evaluated on a 1-4 scale (1= optimal). Results Seventy-eight pediatric outpatients underwent a CCTA scan with the use of metoprolol. The median age was 13 years, median weight of 46 kg, and 36 (46%) were male. The median doses of metoprolol were 1.5 (IQR 1.1, 1.8) mg/kg and 0.4 (IQR 0.2, 0.7) mg/kg for oral and intravenous administrations, respectively. Procedural dose-length product was 57 (IQR 30, 119) mGy*cm. The average reduction in HR was 19 (IQR 12, 26) beats per minute, or 23%. No complications or adverse events were reported. Conclusion Use of metoprolol in a pediatric outpatient setting for HR reduction prior to CCTA is safe and effective. A metoprolol dose protocol can be reproduced when a slower HR is needed, ensuring faster acquisition times, clear images, and associated reduction in radiation exposure in this population. (Arq Bras Cardiol. 2021; 116(1):100-105)

Aplicación forense de tecnología radiográfica dental portátil en Argentina: estado actual y perspectivas futuras / Forensic application of portable dental radiographic technology in Argentina: current status and future prospects

Objetivos: Mensurar los niveles de radiación de fuga y dispersión emanada a través de los blindajes y estructuras plomadas del tubo de rayos X de la unidad dental portátil NOMAD, controlando la retrodispersión con el uso del escudo protector de acrílico plomado adaptado en el extremo final del tubo localizador plomado. Se midieron las tasas de exposición dispersadas mediante un detector tipo Geiger-Müller y una cámara de ionización con respuesta en el rango de energías aportadas en diagnóstico por imágenes para la medición de la exposición directa y determinación posterior de las dosis. Se utilizó un fantomas diseñado para diagnóstico odontológico, sopesando la radiación en diferentes angulaciones de operación del equipo NOMAD, simulando los gestos posturales de odontólogos, radiólogos y sujetos a identificar. Se controlaron las tasas de exposición para determinar los valores de las dosis aportadas en las zonas significativas corporales más radiosensibles del operador del equipo. Se obtuvo como resultado que la retrodispersión en el cristalino del ojo del operador fue significativamente menor cuando el fantomas estaba acostado, mientras que a nivel de gónadas resultó más baja con el cuerpo sentado. La tasa de dosis máxima de radiación dispersa que impactó en los operadores fue de 350.8 micro Sieverts por hora (uSv/h) en la zona de gónadas, por cada radiografía tomada sin el uso del delantal de goma plomada, reduciéndose a 4.38 micro Sieverts por hora (uSv/h) al utilizarlo (AU)

Effects of exposure to low-dose ionizing radiation on changing platelets: a prospective cohort study

BACKGROUND@#Numerous studies have concentrated on high-dose radiation exposed accidentally or through therapy, and few involve low-dose occupational exposure, to investigate the correlation between low-dose ionizing radiation and changing hematological parameters among medical workers.@*METHODS@#Using a prospective cohort study design, we collected health examination reports and personal dose monitoring data from medical workers and used Poisson regression and restricted cubic spline models to assess the correlation between changing hematological parameters and cumulative radiation dose and determine the dose-response relationship.@*RESULTS@#We observed that changing platelet of 1265 medical workers followed up was statistically different among the cumulative dose groups (P = 0.010). Although the linear trend tested was not statistically significant (P@*CONCLUSION@#We concluded that although the exposure dose was below the limit, medical workers exposed to low-dose ionizing radiation for a short period of time might have increased first and then decreased platelets, and there was a dose-response relationship between the cumulative radiation dose and platelets changing.

Design and Test of Automatic Dispensing and Injecting System for Positron Radiopharmaceuticals / 中国医学科学院学报

Objective To design a novel automatic dispensing and injecting system of positron radiopharmaceuticals,for precise dose dispensing,simplified operation,and reduction of occupational radiation exposure. Methods The automatic dispensing and injecting system was fabricated with tungsten alloy as the shielding material.The performance and radiation protection of the device were assessed. Results The total time of injection using the automatic dispensing and injecting system was about 60 s.The ratio of successful injection in stability test was 100%.The deviation of the dispensing dose with the system was ≤3%.With the tungsten alloy shield(40 mmPb of the cabinet,60 mmPb of the countertop,15 mmPb of the protective shield,and 50 mmPb of the inbuilt jar for radiopharmaceuticals),the average dose rate at 30 cm from the device was 1.44 μSv/h,and the radiation dose at the operator's extremity was reduced by 99%. Conclusions This automatic dispensing and injecting system of positron radiopharmaceuticals is easy to operate with precise dispensing dose.It is safe and meets the requirements of radiation protection.

Meso-scale Discovery Assay Detects the Changes of Plasma Cytokine Levels in Mice after Low or High LET Ionizing Irradiation / 生物医学与环境科学（英文）

Objective@#To obtain precise data on the changes in the levels of 29 cytokines in mice after high or low linear energy transfer (LET) irradiation and to develop an accurate model of radiation exposure based on the cytokine levels after irradiation.@*Methods@#Plasma samples harvested from mice at different time points after carbon-ion or X-ray irradiation were analyzed using meso-scale discovery (MSD), a high-throughput and sensitive electrochemiluminescence measurement technique. Dose estimation equations were set up using multiple linear regression analysis.@*Results@#The relative levels of IL-6 at 1 h, IL-5 and IL-6 at 24 h, and IL-5, IL-6 and IL-15 at 7 d after irradiation with two intensities increased dose-dependently. The minimum measured levels of IL-5, IL-6 and IL-15 were up to 4.0076 pg/mL, 16.4538 pg/mL and 0.4150 pg/mL, respectively. In addition, dose estimation models were established and verified.@*Conclusions@#The MSD assay can provide more accurate data regarding the changes in the levels of the cytokines IL-5, IL-6 and IL-15. These cytokines could meet the essential criteria for radiosensitive biomarkers and can be used as radiation indicators. Our prediction models can conveniently and accurately estimate the exposure dose in irradiated organism.

Safety of the effective radiation dose received during stroke hospitalization / Segurança da dose de radiação efetiva recebida durante internação por acidente vascular cerebral

Abstract Background Neuroimaging is widely used for diagnosis and treatment of stroke. However, little is known about whether the radiation doses received by patients comply with international safety guidelines. Objectives The aim of this study was to evaluate the effective radiation dose received while in hospital for stroke and analyze its safety according to current guidelines. Methods This cross-sectional study included 109 patients who were hospitalized and diagnosed with ischemic stroke. The National Institutes of Health Stroke Scale was used to evaluate stroke severity, the Bamford clinical classification was used for topography, and the TOAST classification was used for etiology. The computed tomography dose index and size-specific dose estimates were used to calculate the effective radiation dose (ERD) received while in hospital. A Mann-Whitney test was used to compare the ERD received by thrombolysed and non-thrombolysed patients. Non-parametric statistics were used to analyze the data with a 95% confidence interval. Results During the study period, the median ERD received was 10.9 mSv. Length of stay was not associated with radiation exposure. No differences were demonstrated in ERD according to stroke etiology or Bamford clinical classification. Patients who had CT perfusion (only or in addition to CT or angiotomography) received the highest ERD (46.5 mSv) and the difference compared to those who did not (10.8 mSv) was statistically significant (p<0.001). No differences were found in the ERD between thrombolysed and non-thrombolysed patients. There was no correlation between ERD while in hospital and stroke severity. Conclusions According to the current national guidelines, the protocol for examining images at our stroke unit is safe in terms of the ERD received by the patient while in hospital. There was no difference in the ERD received by patients stratified by thrombolytic treatment or stroke severity.

Resumo Contexto A neuroimagem é amplamente utilizada para o diagnóstico e tratamento do acidente vascular cerebral (AVC). No entanto, pouco se sabe se a dose de radiação recebida nesses exames está de acordo com as diretrizes internacionais de segurança. Objetivos O objetivo deste estudo foi avaliar a dose de radiação efetiva (DRE) durante a hospitalização por AVC. Métodos Trata-se de estudo transversal com 109 pacientes hospitalizados com diagnóstico de AVC isquêmico. A gravidade do AVC foi avaliada pela National Institutes of Health Stroke Scale, a topografia pela classificação clínica de Bamford e a etiologia pelo Trial of ORG 10172 in Acute Stroke Treatment (TOAST). O índice de dose recebida no exame de tomografia computadorizada (TC) e as estimativas de dose específicas foram usados ​​para calcular a DRE recebida durante a hospitalização. O teste de Mann-Whitney foi utilizado para comparar a DRE recebida por pacientes trombolisados ​​e não trombolisados. Estatísticas não paramétricas foram utilizadas para analisar os dados. Resultados Durante o período do estudo, a DRE foi de 10,9 mSv. O tempo de internação não foi associado à exposição à radiação. Nenhuma diferença foi demonstrada na DRE de acordo com a etiologia e classificação clínica de Bamford. Os pacientes que fizeram perfusão (isolada, associada à TC ou angiotomografia) receberam a maior DRE (46,5 mSv) em comparação aos que não fizeram (10,8 mSv), sendo estatisticamente significativo (p <0,001). Não foram encontradas diferenças na DRE entre pacientes trombolisados e não trombolisados. Não houve correlação entre a DRE durante a hospitalização com a gravidade do AVC. Conclusões De acordo com as atuais diretrizes nacionais, o protocolo de exame de imagens na unidade de AVC é seguro em relação à DRE recebido pelo paciente durante a internação. Não houve diferença na DRE dos pacientes de acordo com o tratamento trombolítico e a gravidade do AVC.

Padronizando a Exposição à Radiação durante o Cateterismo Cardíaco em Crianças com Cardiopatia Congênita: Dados de um Registro Multicêntrico Brasileiro / Standardizing Radiation Exposure during Cardiac Catheterization in Children with Congenital Heart Disease: Data from a Multicenter Brazilian Registry

Resumo Fundamento Nos últimos anos, o recente aumento no número de procedimentos intervencionistas tem resultado em crescente preocupação em relação à exposição radiológica por pacientes e equipe médica. A avaliação da exposição dos níveis de radiação em crianças é difícil devido à grande variabilidade no peso corporal. Portanto, os valores de referência de radiação não estão bem definidos para essa população. Objetivos Avaliar e validar a razão do produto dose-área (DAP) em relação ao peso corporal como uma medida de referência de radiação em cateterismos cardíacos em crianças. Métodos Estudo multicêntrico observacional com dados do Registro Brasileiro de Cateterismo Cardíaco em Cardiopatias Congênitas (CHAIN) de março de 2013 a junho de 2014. Os critérios de inclusão foram: pacientes <18 anos submetidos a procedimentos hemodinâmicos para cardiopatia congênita, com DAP devidamente registrado. Foram considerados diferenças estatísticas significativas os valores de p < 0,05. Resultados Este estudo avaliou 429 pacientes com idade e peso medianos de 50 (10, 103) meses e 15 (7, 28) kg, respectivamente. O DAP mediano foi de 742,2 (288,8, 1.791,5) μGy.m2. Houve uma boa correlação entre o DAP e o produto peso/tempo de fluoroscopia (rs=0,66). Não foi observada diferença estatisticamente significativa na relação DAP/peso entre procedimentos terapêuticos e diagnósticos. Houve ampla variação da relação DAP/peso entre os procedimentos terapêuticos (p<0.001). Conclusões A proporção DAP/peso é a medida mais simples e aplicável para avaliar a exposição radiológica em uma população pediátrica. Apesar da escassa literatura disponível, as doses obtidas no presente estudo foram semelhantes àquelas encontradas anteriormente. Estudos de validação e comparação são importantes na avaliação do impacto de estratégias para redução da exposição radiológica nessa população. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)

Abstract Background In recent years the increasing number of interventional procedures has resulted in growing concerns regarding radiation exposure for patients and staff. The evaluation of radiation exposure in children is difficult due to the great variability in body weight. Therefore, reference levels of radiation are not well defined for this population. Objectives To study and validate the ratio of dose-area product (DAP) to patient weight as a reference measurement of radiation for hemodynamic congenital heart disease procedures in children. Methods This observational multicenter study uses data obtained from a Brazilian registry of cardiac catheterization for congenital heart disease from March 2013 to June 2014. Inclusion criteria were all patients aged <18 years old undergoing hemodynamic procedures for congenital heart disease, with recorded DAP doses. P-value < 0.05 was considered as statistically significant. Results This study evaluated 429 patients with median age and weight of 50 (10, 103) months and 15 (7, 28) kg, respectively. Median DAP was 742.2 (288.8, 1,791.5) μGy.m2. There was a good correlation between DAP and weight-fluoroscopic time product(rs=0.66). No statistically significant difference was observed in DAP/weight ratio between therapeutic and diagnostic procedures. There was a wide variation in the DAP/weight ratio among the therapeutic procedures (p<0.001). Conclusions The DAP/weight ratio is the simplest and most applicable measurement to evaluate radiation exposure in a pediatric population. Although there is limited literature available, the doses obtained in the present study were similar to those previously found. Ongoing research is important to evaluate the impact of strategies to reduce radiation exposure in this population (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)