Algae Metabolites as an Alternative in Prevention and Treatment of Skin Problems Associated with Solar Radiation and Conventional Photo-protection

Abstract The histological structure and biochemistry of the skin is affected by solar radiation having adverse effects ranging from sunburns, premature aging that includes wrinkles, spots, dryness, and loss of collagen to cancer development. The skin has defense mechanisms to prevent damage caused by radiation, but when radiation exposure is excessive these mechanisms are not strong enough to protect the skin. The use of sunscreen is the most common practice of photo- protection. The active ingredients of these cosmetic protective formulations are generally from synthetic origin and have presented several drawbacks at the level of photo-stability, systemic absorption and can generate contact and photo-contact dermatitis. This review illustrates skin solar radiation problems, common sunscreen ingredients limitation and mentions how algae can be an alternative according to studies that have evaluated the photo-protective potential of extracts and compounds isolated by different techniques.

Characterization of Geiger-Müller radiation detectors response at the University of Costa Rica's Cyclotron Facilities / Caracterización de la respuesta de detectores de radiación Geiger-Müller en el Ciclotrón de la Universidad de Costa Rica

To ensure a reliable verification of a radiation detector, the right parameters for this response verification must be determined and a specific characterization on the detectors of interest must be performed. These were the main pillars of this study, where four Geiger-Müller at the University of Costa Rica's Cyclotron Facilities' main laboratories were studied and characterized using a 137Cs source. First, a verification of the inverse-square law was performed to corroborate the correct measurement by the detectors as the distance from a 137Cs source to the detectors was varied using a new design for a positioner support to ensure repeatability. This verification yielded a potential fit curve with and equation D=670635 x-1.961 (error percentage of 1.95%) and an R2 value of 0.9836. Then, using combinations of copper plates of widths 1.0 mm and 2.0 mm as attenuators between the source and the detectors, the mass attenuation coefficient for copper was obtained only as a reference value for future calibrations of the detectors. The result for this value was 0.040 cm2 /g. The results obtained in this study and the method developed to achieve these results will serve as a base for calibrations of the detectors at these facilities, which will ensure the safety of the patients and personnel in this building.

Para asegurar respuesta correcta de un detector de radiación, se deben determinar los parámetros correctos para esta verificación y debe realizarse una caracterización específica de los detectores de interés. Estos fueron los pilares principales de este estudio, donde se estudiaron y caracterizaron 4 detectores Geiger-Müller en los laboratorios principales del Ciclotrón de la Universidad de Costa Rica utilizando una fuente radiactiva de 137Cs. Primero, se realizó una verificación de la ley del inverso-cuadrado para corroborar la medición correcta de los detectores según se varía la distancia entre la fuente de 137Cs al detector utilizando un diseño nuevo de un soporte posicionador para la fuente que asegura la repetibilidad entre experimentos. Esta verificación resultó en una curva de ajuste potencial de ecuación D=670635x-1,961 (porcentaje de error de 1,95%) y un valor de R2 de 0,9836. Luego, utilizando combinaciones de placas de cobre de espesores 1,0 mm y 2,0 mm como atenuadores entre la fuente y los detectores, se obtuvo el coeficiente de atenuación másico para el cobre como un valor de referencia para futuras calibraciones de los detectores. Este resultado fue de 0,040 cm2/g. Los resultados obtenidos en esta investigación y el método desarrollado para lograr estos resultados servirán como una base para una futura confirmación metrológica calibraciones de los detectores en estos laboratorios, lo cual colaborará con la seguridad y protección radiológica de pacientes y trabajadores en este edificio.

Niveles de Referencia para Diagnóstico en Procedimientos Radiológicos Dentales: Una Guía Práctica / Diagnostic Reference Levels in Dental Radiological Procedures: A Practical Guide

RESUMEN: Las exposiciones médicas con radiación ionizante son actualmente la principal fuente de exposición a la radiación artificial a nivel global, entre ellas, los exámenes dentales corresponden a uno de los más frecuentes. Para prevenir dosis innecesariamente altas a los pacientes durante estas exposiciones, la Comisión Internacional de Protección Radiológica (ICRP) recomienda la utilización de Niveles de Referencia para Diagnóstico (DRLs), como una herramienta efectiva de ayuda a la optimización de la protección radiológica en la exposición médica de pacientes. Dado que la legislación de Chile aún no ha incorporado el uso de los DRLs, el presente trabajo de revisión tuvo como objetivo analizar la publicación N° 135 de la ICRP para generar un documento que sirva de guía para los odontólogos, explicando de manera didáctica y en un lenguaje sencillo, pero técnico, los principales aspectos a tener en cuenta para establecer los DRLs en procedimientos de radiología dental.

SUMMARY: Currently exposure to ionizing radiation is currently the main source of exposure to artificial radiation worldwide, with dental examinations being one of the most frequent events. In order to prevent exposure of unnecessarily high doses in patients, the International Commission on Radiological Protection (ICRP) recommends the use of Diagnostic Reference Levels (DRLs), as an effective tool to help maximize protection from radiation during medical exposure of patients. Given that the Chilean legislation has not yet incorporated the use of DRLs, the purpose of this study was to analyze publication N° 135 of the ICRP to generate a document, to serve as a guide for dentists, didactically outlining in simple but technical language, the main aspects to consider when establishing DRLs in dental radiology procedures.

Non-use of sunscreen among adults and the elderly in southern Brazil

Abstract Background One of the main prevention methods against skin cancer is the use of sunscreen; however, incidence of this disease has not declined despite prevention campaigns. Objective Investigate the prevalence of non-use of sunscreen and its associated factors. Method A population-based cross-sectional study with individuals aged 18 years or over living in the urban area. Conducted between April and July of 2016. Participants were interviewed about socioeconomic, demographic, and behavioral questions. Non-use of sunscreen was considered as the outcome. For multivariate analysis, Poisson regression with robust adjustment for variance was used. Results Among the 1300 participants, prevalence of non-use of sunscreen was 38.2% (95% CI: 34.6-41.8). The variables independently associated with the outcome were male sex, older age, brown or black skin color, lower income, fewer years of education, no physical activity in leisure time, no medical consultations in the last year, and self-perception of health as regular or poor. Study limitations The prevalence may be underestimated by reports of more use of sunscreen than actually used, which could increase the figure in the outcome. Conclusion It was estimated that about four out of ten adults and elderly do not use sunscreen in this sample. Prevention strategies are needed to advance health policy and ensure that sun protection options are easily accessible.

Development and validation of an instrument to assess the knowledge of general practitioners and pediatricians about photoprotection and solar radiation

Abstract Background The knowledge of general practitioners about photoprotection is unknown. Objectives To develop and validate an instrument to evaluate the knowledge of general practitioners and pediatricians about photoprotection, gauging the knowledge of these professionals. Methods The study followed the steps: (1) Literature identification and item elaboration related to the theme; (2) Content validation; (3) Apparent validation; (4) Construct validation: internal consistency analysis and discriminatory analysis; (5) Reliability analysis. In Step 4, the instrument was applied to 217 general practitioners and pediatricians who worked in the host city of the study; the scores were compared with dermatologists scores. Results The final instrument had 41 items and showed satisfactory internal consistency (Cronbach's alpha = 0.780), satisfactory reproducibility and good test-retest reliability (good-to-excellent kappa statistic in more than 60% of items). The discriminatory analysis registered a mean score of 54.1 points for dermatologists and 31.1 points for generalists and pediatricians, from a total of 82 possible points, representing a statistically significant difference (p < 0.001). Generalists and pediatricians demonstrated an understanding of the relationship between excessive sun exposure and skin cancer, but they revealed lack of technical information necessary for their professional practice. Study limitations The instrument evaluates only knowledge, without evaluating the conduct of the participants. Conclusion The results show that the instrument has good internal consistency and good reproducibility. It could be useful in the identification of general practitioners and pediatricians knowledge gaps on the subject, for the subsequent development of training and educational strategies.

Prevalance of papillary thyroid carcinoma among patients underwent thyroidectomy and its relative relation to medical Z-Ray exposure

Background: The papillary thyroid carcinoma is the most common cancer among well-differentiated thyroid carcinoma. Exposure to environmental radiation adn edical X-Ray can be considered as an iportant risk factor. The aim of the study to evaluate the prevalence of papillary thyroid carcinoma among patients underwent thyroidetomy and the possible relation to X-Ray exposure. Patient and methods: A prospective clinically randomized trial was conducted in the department of surgery in Diwaniyah Teaching Hospital during the period from February 2016 to October 2018 on 432 patients with goiter from those 62 patients proved to be papillary thyroid carcinoma. Results: out of 432 patients with goiter underwent thyroidectomy 62 patients proved to be papillary carcinoma, female was 49 (79 %), and male was 13 (21%) with solitary thyroid nodule predominant (61.3%) the radiation exposure is higgly significant in patients proved to be papillary thyrid carcinoma about (85.48%), the FNAC sensitivity was low about 37%. There were 14 patients re-explored either for remnant thyroid tissue in 11 or neck disection in 3 patients. Only there patients presented with occult papillary thyroid carcinoma. Conclusion: Papillary thyroid carcinoma is the most common thyroid malignancy with salient increased incidence and female predominant in this region. X-ray exposure carries a significant risk factor for thyroid malignancy. However, further national clinical studies recommended confirming the results

Seguridad y Protección Radiológica en Procedimientos Imagenológicos Dentales / Safety and Radiological Protection in Dental Imaging Procedures

RESUMEN: Los procedimientos de imagenología dental son el tipo más frecuente de estudio radiológico y aportan información esencial para apoyar la evaluación, diagnóstico y tratamiento de patologías y/o alteraciones dentomaxilofaciales. La presente revisión narrativa, muestra los procedimientos de radiología dental, define conceptos asociados a la protección radiológica en éstos y entrega una guía con recomendaciones para mejorar la seguridad y protección radiológica del paciente y del operador, en esta clase de procedimientos imagenológicos. Comprender que bajo el actual sistema de protección radiológica, es el Odontólogo quién debe justificar la realización o no de un tipo de procedimiento radiológico, teniendo presente los costos económicos y sobre todo los costos en términos de dosis para el paciente.

ABSTRACT: Dental imaging procedures are the most frequent type of radiological study and provide essential information to support the evaluation, diagnosis and treatment of pathologies and / or dentomaxillofacial alterations. The present narrative review shows dental radiology procedures, defines concepts associated with radiological protection in these and provides a guide with recommendations to improve the safety and radiological protection of the patient and the operator in this kind of imaging procedures. Understanding that under the current system of radiological protection, it is the dentist who must confirm the realization or not, of a type of radiological procedure, keeping in mind the financial costs, and above all, consequences to the patient in terms of dose used in the procedure.

Informe sobre la radio-exposición en el personal quirúrgico de Ortopedia y Traumatología: Principios, marco legal y análisis situacional en la Argentina / Report on the radiation exposure in Orthopedic and Traumatology surgical staff. Principles, legal framework, and situational analysis in Argentina

La cirugía ortopédica ha avanzado mucho en estos años y, con ello, el uso de la intensificación de imágenes en el quirófano. El objetivo de este informe es revisar los principios biológicos de la radiación, el marco legal actual y hacer una breve reseña sobre la situación actual en la Argentina.

Orthopedic surgery has significantly advanced in the past years along with image intensifier fluoroscopy in the operating room. The purpose of this report is to review biological principles of radiation, as well as the current legal framework and to outline the present situation in Argentina.

Magnitudes y unidades para dosimetría del personal ocupacionalmente expuesto en radiodiagnóstico e intervencionismo / Quantities and units for dosimetry of occupationally exposed personnel in diagnostic and interventional radiology

Resumen:Existen diversos documentos y recomendaciones internacionales sobre nombres, conceptos, definiciones y campos de aplicación para diversas magnitudes y unidades utilizadas para monitorear los niveles de radiación ionizante a los que son expuestos los trabajadores durante los procedimientos de Radiodiagnóstico e Intervencionismo. Sin embargo, la legislación nacional, al igual que para la dosimetría de los pacientes, no se encuentra actualizada en este sentido y no contempla en sus documentos un glosario actualizado que permita encontrar en forma rápida y precisa este tipo de información. Por lo anterior, este trabajo de revisión corresponde a un segundo documento guía, complementario a nuestro trabajo publicado en 2015 titulado "Magnitudes y unidades para dosimetría a pacientes en radiodiagnóstico e intervencionismo", que describe de manera didáctica y en un lenguaje sencillo para los profesionales de la salud y áreas afines, las principales magnitudes y unidades que se deben conocer y utilizar en la dosimetría ocupacional de los trabajadores que participan en procedimientos de Radiodiagnóstico e Intervencionismo.

Abstract: There are many documents and international recommendations offer names, concepts, definitions and fields of application for various quantities and units used to monitor the exposure levels of ionising radiation to which workers are exposed during the diagnostic and interventional radiology procedures. However, as in the case of patient dosimetry, national legislation is not up-to-date in this area and nowhere does it establish an up-to-date glossary that would facilitate rapid and precise location of this kind of information. In light of the foregoing, this review paper presents a second guidance document, complementary to our published article in 2015 titled "Quantities and units used in patient dosimetry in radiodiagnostic and intervencional procedures", which describes the principal quantities and units that must be known and used in occupational dosimetry for workers participating in diagnostic and interventional radiology procedures, in a didactical manner and using simple language for professionals in health and similar areas.

Campanha e carteira de radioproteção: estratégias educativas que reduzem a exposição excessiva de crianças a exames radiológicos / Radioprotection campaign and card: educational strategies that reduce children's excessive exposure to radiological exams

RESUMO Objetivos: Analisar resultados de iniciativa para racionalizar o uso de exames radiológicos, garantindo sua qualidade técnica, e implantar uma campanha de radioproteção que inclua a capacitação da equipe profissional e a Carteira de Radioproteção para crianças de até 12 anos como instrumento para que os pais e médicos controlem a exposição das crianças à radiação. Métodos: Em um sistema de saúde suplementar com cobertura de 140 mil pessoas, foi implantada a campanha de radioproteção com base nos protocolos Image Gently •, garantindo a menor dose possível de exposição à radiação, com qualidade técnica, e implantando a Carteira de Radioproteção. Para aferir a eficácia dessas ações, comparou-se o número de exames radiológicos realizados no setor de urgência e emergência pediátrica no período de um ano anterior à campanha com o número de exames radiológicos realizados no período de um ano posterior à campanha. Resultados: As ações foram bem-aceitas por todos os grupos envolvidos. No ano seguinte à implantação das estratégias de radioproteção, observou-se redução de 22% no número de exames radiológicos realizados no setor pediátrico de urgência e emergência. Houve ainda diminuição de 29% da solicitação de dois ou mais exames para a mesma criança ou de exames com duas ou mais incidências. Conclusões: A campanha de radioproteção e a implantação da Carteira de Radioproteção para crianças até 12 anos revelaram-se estratégias factíveis e associaram-se à redução dos exames radiológicos solicitados e realizados no setor de urgência e emergência pediátrica.

ABSTRACT Objectives: To analyze the results of an initiative aimed at improving the reasonable use of radiological examinations, ensuring their technical quality, implementing a radioprotection campaign that includes training of the professional team, and introducing the radioprotection card for children under 12 years old as a tool for parents and doctors to control children's exposure to radiation. Methods: The study was held in a health care insurance system covering 140,000 people. A radioprotection campaign was implemented according to Image Gently • protocols, ensuring the lowest dose of radiation and the quality of examinations, and the radioprotection card was implemented. To assess the effectiveness of these actions, the number of radiological examinations performed at the pediatric emergency room in a period of one year preceding the campaign was compared with the number of radiological examinations performed one year after the campaign. Results: The campaign was well accepted by all professionals, families, and patients involved. In the year following the implementation of radioprotection strategies, there was a 22% reduction of radiological examinations performed at the pediatric emergency room. There was also a 29% reduction in the request of two or more radiological examinations for the same child or examinations with two or more incidences. Conclusions: The campaign and the radioprotection card for children under 12 years old proved to be feasible strategies and correlated with a reduction in radiological examinations requested and performed at the pediatric emergency room.

Avaliação do conhecimento de acadêmicos de medicina sobre os riscos da exposição ocupacional à radiação ionizante / Evaluation of medical students' knowledge about the risks of occupational exposure to ionizing radiation

Introdução: A despeito do conhecimento já consolidado sobre os riscos associados à exposição às radiações ionizantes, estudos demonstram que estudantes e profissionais de saúde negligenciam ações de proteção à radiação ionizante. A pesquisa realizada teve como objetivo geral avaliar o conhecimento de acadêmicos de Medicina sobre a exposição ocupacional à radiação ionizante no início, meio e final do curso. Métodos: Estudo observacional de tipo transversal com aplicação de questionários para 345 acadêmicos do curso de Medicina da Universidade do Sul de Santa Catarina ­ Unisul, no ano de 2015. Resultados: A maioria dos alunos respondeu que o tema radiação ionizante foi oferecido em algumas disciplinas do curso, contudo esta resposta foi mais prevalente entre os alunos de fases iniciais e intermediárias. Alunos das fases finais julgaram, em sua maioria, seu conhecimento sobre os efeitos nocivos da radiação como "sofrível". Conclusões: A percepção dos alunos do curso avaliado foi a de que o conhecimento adquirido ao longo do curso de Medicina não contribuiu para adesão a precauções e cuidados universais em relação à proteção contra os efeitos das radiações ionizantes no futuro profissional. A inclusão de informações sobre o tema ao longo do curso pode alterar a situação observada nos egressos desta universidade (AU)

Introduction: Despite the already consolidated knowledge about the risks associated with exposure to ionizing radiation, studies show that students and health professionals neglect protective actions against ionizing radiation. The aim of this study was to evaluate the medical students' knowledge about occupational exposure to ionizing radiation at the beginning, middle and end of the course. Method: A cross-sectional observational study with questionnaires for 345 medical students from the University of Southern Santa Catarina ­ Unisul, in the year 2015. Results: Most students answered that the topic of ionizing radiation was offered in some disciplines of the course. However, such answer was more prevalent among students at the initial and intermediate stages. Most students at the final stages considered their knowledge about the harmful effects of radiation as "poor". Conclusions: The students' perception of the evaluated course was that the knowledge acquired during the course of medicine did not contribute to adherence to precautions and universal care for protection against the effects of ionizing radiation by the future practitioner. The inclusion of information on the subject throughout the course may change the situation observed in the graduates of this university (AU)

¿Es eficiente la protección anti-radiación otorgada por gorros de pabellón de tungsteno-bismuto en cardiología intervencionista? / Radiation protection provided by tungsten bismuth caps during interventional cardiology

Background: The effectiveness against radiation of tungsten bismuth caps, used in interventional cardiology is not well known. Aim: To determine the degree of radiation protection conferred by these caps in real work conditions. Material and Methods: We compared the gross electric charges received at brain lobe levels by three occupationally exposed professionals who participated in 22 consecutive procedures, inside and outside of the tungsten bismuth cap. Results: The median electric charges outside and inside the cap were 3.71 (range 1.46-5.62) and 2.2 (range 1.29-3.93) nC, which correspond to a 40% radiation attenuation. However, the protection was heterogeneous. Conclusions: Tungsten bismuth caps provide an adequate attenuation, but its degree is heterogeneous.

Efficacy Analysis of a Script-based Guide for EVAR Execution: is it Possible to Reduce Patient Exposure to Contrast, Operative Time and Blood Loss even when Advanced Technologies are not Available?

ABSTRACT INTRODUCTION: Despite the patient and medical staff exposure to radiation in endovascular aneurysm repair, the benefits of this abdominal aortic aneurysm type of surgical management are justfied by minor recovery time and hospitalization, as well as an option for patients not elected to conventional open repair. In this minimally invasive surgical aproach, time of procedure and radiation doses can be substantial - and the increasing frequency of these procedures and it's complexity have impelled vascular surgeons to face additional and successive risk to occupational radiation exposure. Meticulous study of the computed tomography angiography during the endovascular aneurysm repair preparation allows reduction of unnecessary radiation exposure, as also reduces consecutive image acquisition and contrast use (that may be related to renal overload in susceptible patients). Some studies have proposed strategies to optimize endovascular intervention to reduce contrast use and X-ray exposure. Although they might prove to be effective, they rely on use of additional specific and advanced equipment, available only in major centers. As an alternative to this expensive and restrict technology, it is presented a simpler technique through image manipulation on software OsiriX, aiming to reduce both exposures. OBJECTIVE: To analyze the efficacy of the adoption of a study protocol and a script-based guide in preparation for endovascular aneurysm repair through verifying it's impact over the surgical procedure - as referred to intravascular contrast infuse, effects over renal function, blood loss and operatory time. METHODS: A longitudinal prospective study from March 2014 through March 2015, where 30 performed endovascular aneurysm repair were compared to a historic control group. The planning for endovascular aneurysm repair through the patient's tomographic image manipulation in the prospective group was performed with OsiriX MD software. A script-based guide upon gathering detailed computed tomography angiography images was elaborated by the author and distributed to the performing surgical team for appreciation, instruction and pre operatory judgment. Based upon the script, the C-arm gantry angle was specifically corrected in each case of endovascular aneurysm repair, for image optimization and aneurysm's neck visualization. Arteriography was performed under digital subtraction angiography after catheters were positioned according to predicted level description in the referred guide. Statistical analysis were performed with a significance level of 5% (P value<0.05). RESULTS: There was a statistically significant relationship between the two studied periods and the variables: contrast volume (284.5 vs. 31.8 mL), operative time (207.5 vs. 140.4 min.) and blood loss (798.1 vs. 204.4 mL), revealing that they are considerably larger in the historical control group than in the script guided current group. There was no difference related to the volume of contrast used in the two groups and the occurrence of renal impairment. CONCLUSION: In the present paper it was possible to demonstrate the impact of the ability to manipulate digital formats of medical images without the need of sophisticated equipment, in adoption of a guide based on the compilation of informations collected with assistance of an accessible software performed on a personal computer. Although we could not prove relation to occurrence of renal impairment, there were direct results on reduction of intravascular contrast use, even as surgical time and blood loss, compared to a previous historical period.

Does Ad Hoc Coronary Intervention Reduce Radiation Exposure? – Analysis of 568 Patients / Intervenção Coronariana Ad Hoc Reduz a Exposição Radiológica? - Análise em 568 Pacientes

Background:Advantages and disadvantages of ad hoc percutaneous coronary intervention have been described. However little is known about the radiation exposure of that procedure as compared with the staged intervention.Objective:To compare the radiation dose of the ad hoc percutaneous coronary intervention with that of the staged procedureMethods:The dose-area product and total Kerma were measured, and the doses of the diagnostic and therapeutic procedures were added. In addition, total fluoroscopic time and number of acquisitions were evaluated.Results:A total of 568 consecutive patients were treated with ad hoc percutaneous coronary intervention (n = 320) or staged percutaneous coronary intervention (n = 248). On admission, the ad hoc group had less hypertension (74.1% vs 81.9%; p = 0.035), dyslipidemia (57.8% vs. 67.7%; p = 0.02) and three-vessel disease (38.8% vs. 50.4%; p = 0.015). The ad hoc group was exposed to significantly lower radiation doses, even after baseline characteristic adjustment between both groups. The ad hoc group was exposed to a total dose-area product of 119.7 ± 70.7 Gycm2, while the staged group, to 139.2 ± 75.3 Gycm2 (p < 0.001).Conclusion:Ad hoc percutaneous coronary intervention reduced radiation exposure as compared with diagnostic and therapeutic procedures performed at two separate times.

Fundamento:Uma série de vantagens e desvantagens tem sido descrita para a intervenção coronária percutânea ad hoc, como a realizada ao mesmo tempo que o cateterismo diagnóstico, porém pouco se sabe sobre a exposição radiológica desse procedimento, comparado com a intervenção estadiada, ou seja, em dois momentos.Objetivo:Comparar a dose de radiação utilizada na angioplastia ad hoc com a angioplastia estadiada.Métodos:O produto de dose por área e o Kerma total foram mensurados, somando-se ambas as fases de diagnóstico e terapêutica. Além disso, foram computados o tempo total de fluoroscopia e o número de filmagens.Resultados:Um total de 568 pacientes consecutivos foram tratados com intervenção coronária percutânea ad hoc (n = 320) ou estadiada (n = 248). À admissão, o grupo do ad hoc apresentava menos hipertensão (74,1% vs. 81,9%; p = 0,035), dislipidemia (57,8% vs. 67,7%; p = 0,02) e doença triarterial (38,8% vs. 50,4%; p = 0,015). O grupo ad hoc foi exposto a doses significativamente menores de radiação, mesmo após ajuste para as diferenças basais entre os grupos. O grupo ad hoc foi exposto a uma dose de produto de dose por área total de 119,7 ± 70,7 Gycm2 enquanto que os pacientes estadiados foram expostos a uma dose de 139,2 ± 75,3 Gycm2 (p < 0,001).Conclusão:A intervenção coronária percutânea ad hoc reduziu a exposição radiológica, em comparação com procedimentos diagnósticos e terapêuticos realizados em tempos separados.

The Benefits of Prone SPECT Myocardial Perfusion Imaging in Reducing Both Artifact Defects and Patient Radiation Exposure / Benefício da Aquisição de Imagem na Posição Prona em Perfusão Miocárdica com SPECT para Redução de Artefatos e Exposição do Paciente à Radiação

AbstractBackground:Prone imaging has been demonstrated to minimize diaphragmatic and breast tissue attenuation.Objectives:To determine the role of prone imaging on the reduction of unnecessary rest perfusion studies and coronary angiographies performed, thus decreasing investigation time and radiation exposure.Methods:We examined 139 patients, 120 with an inferior wall and 19 with an anterior wall perfusion defect that might represented attenuation artifact. Post-stress images were acquired in both the supine and prone position. Coronary angiography was used as the “gold standard” for evaluating coronary artery patency. The study was terminated and rest imaging was obviated in the presence of complete improvement of the defect in the prone position. Quantitative interpretation was performed. Results were compared with clinical data and coronary angiographic findings.Results:Prone acquisition correctly revealed defect improvement in 89 patients (89/120) with inferior wall and 12 patients (12/19) with anterior wall attenuation artifact. Quantitative analysis demonstrated statistically significant difference in the mean summed stress scores (SSS) of supine and mean SSS of prone studies in patients with disappearing inferior wall defect in the prone position and patent right coronary artery (true negative results). The mean difference between SSS in supine and in prone position was higher with disappearing than with remaining defects.Conclusion:Technetium-99m (Tc-99m) tetrofosmin myocardial perfusion imaging with the patient in the prone position overcomes soft tissue attenuation; moreover it provides an inexpensive, accurate approach to limit the number of unnecessary rest perfusion studies and coronary angiographies performed.

ResumoFundamento:Já foi demonstrado que a imagem na posição prona minimiza a atenuação dos tecidos diafragmáticos e da mama.Objetivos:Determinar o papel da imagem na posição prona na redução de estudos de perfusão em repouso e angiografias coronárias realizadas de forma desnecessária, assim diminuindo o tempo de investigação e exposição à radiação.Métodos:Foram examinados 139 pacientes, 120 com um defeito de perfusão da parede inferior e 19 com defeito de perfusão da parede anterior que pudessem representar um artefato de atenuação. Imagens pós-estresse foram adquiridas nas posições supina e prona. A angiografia coronária foi usada como o “padrão ouro” para avaliar a patência da artéria coronária. O estudo foi encerrado e a imagem em repouso não foi necessária na presença de melhoria completa do defeito na posição prona. Uma interpretação quantitativa foi realizada. Os resultados foram comparados com os dados clínicos e achados angiográficos.Resultados:A aquisição de imagem na posição prona revelou corretamente a melhoria do defeito em 89 pacientes (89/120) com artefato de atenuação na parede inferior e 12 pacientes (19/12) na parede anterior. A análise quantitativa demonstrou diferença estatisticamente significante nas somas dos escores de estresse (SSS) médios nos estudos da posição supina e SSS médios dos estudos na posição prona em pacientes com desaparecimento do defeito da parede inferior na posição prona e artéria coronária patente (resultados negativos verdadeiros). A diferença média dos SSS nas posições supina e prona foi maior com os defeitos desaparecidos do que com os que permaneceram.Conclusão:A cintilografia de perfusão miocárdica com Tecnécio-99m (Tc-99m) tetrofosmin com o paciente na posição prona supera a atenuação de tecidos moles; Além disso, oferece uma abordagem precisa e de baixo custo para limitar o número de estudos de perfusão em repouso e realização de angiografias coronárias desnecessárias.

Exposición radiológica en urología: conocimientos y medidas preventivas generales en Chile / Radiation exposure in urology: knowledge and general preventive measures in Chile

Existe una creciente exposición a la radiación ionizante en la práctica médica habitual tanto para el paciente como para el médico tratante, debido a un incremento en exámenes imagenológicos solicitados como al uso de rayos X como soporte en procedimientos y cirugías. Parte importante de la práctica médica en urología involucra exposición a radiación. Por este motivo, decidimos evaluar el nivel de conocimientos y medidas preventivas que realizan los urólogos y residentes de urología en Chile al exponerse a la radiación. MATERIAL Y MÉTODO: Se aplicó una encuesta a residentes de urología y urólogos que ejercen dicha especialidad en Chile. Esta encuesta fue aplicada de manera voluntaria y anónima vía e-mail y evaluó los conocimientos generales y medidas preventivas frente a la exposición radiológica. Se analizan resultados según año de residencia y nivel de formación académica. RESULTADOS: Existe un bajo nivel de conocimientos y de prácticas preventivas de tanto los residentes como especialistas encuestados en el tema de protección radiológica. No se observaron diferencias significativas entre los distintos niveles de formación. CONCLUSIÓN: Se detectó un bajo nivel de conocimiento y un bajo empleo de medidas preventivas. Se postula la necesidad de incorporar un curso obligatorio de exposición radiológica durante la residencia de urología.

There has been an increase in the exposure to ionizing radiation in current medical practice in the past few decades. This raise is the result of an increase in the amount of radiological images solicited and use of X-rays in procedures and surgeries. Clinical practice in urology involves high levels of exposure. We decided to evaluate knowledge and preventive measures when urology specialists and residents are exposed to radiation. MATERIALS AND METHODS: A survey previously utilized in international centers for similar purposes was applied to urology residents and specialists that practice medicine in Chile. This survey was applied electronically via email and evaluated general knowledge and preventive measures when exposed to ionizing radiation. Results are analyzed between years of residency and academic formation. RESULTS: A low level of knowledge and preventive measures were detected among both urology residents and specialists. No significant differences were observed when analyzing results according to year of residency. CONCLUSION: Given the low level of knowledge and preventive measures utilized when exposed to radiation, we propose to include an obligatory course in radiologic exposure during urology residency.

Interacciones de las radiaciones electromagnéticas y especies reactivas del oxígeno sobre la piel / Interactions of electromagnetic radiations and reactive oxygen species on skin

La energía radiante abarca todo el espectro electromagnético y proviene de la fusión en el sol, de 4 núcleos de hidrógeno en uno de helio. Las radiaciones electromagnéticas tienen características de ondas, con la velocidad de la luz (c) y difieren en sus longitudes de ondas (λ). La energía lumínica es transmitida en unidades individuales o fotones: E = h c/λ así, los fotones de menores λs son los de mayor energía. Las radiaciones ultravioletas (UV) (λs de 200 - 400 nm) pueden dividirse: UVA (λs 315 - 400 nm); UVB (λs 280 - 315 nm) y UVC (λs < 280 nm). UVB y UVC son las más importantes, en inducir respuestas biológicas. Por acción de las radiaciones electromagnéticas el O2, da productos agrupados bajo la denominación de Especies Reactivas del Oxígeno (ROS). El alto contenido de O2 en los sistemas biológicos estimula la formación de ROS, que si no son controladas por el sistema endógeno de antioxidantes, afectan el estado redox de las células y generan daños tisulares ("stress oxidativo"). Inducen peroxidación de lípidos, entrecruzamiento de proteínas, inhibición de enzimas, pérdida de integridad y función de membranas plasmáticas y mitocondriales, ruptura de organelas intracelulares. Como consecuencias producen inflamación, envejecimiento, carcinogénesis y muerte celular. Mientras las radiaciones infrarrojas, inducen aumento de la temperatura cutánea, llegando a producir graves quemaduras, las UVA y UVB, en forma encubierta, reaccionan con cromóforos del tejido cutáneo, que absorben fotones y generan alteraciones fotoquímicas, implicadas en el envejecimiento celular e inducción de cáncer. La radiación UV al alcanzar el núcleo de las células causa daños en el ADN. Los seres humanos debemos protegernos de los efectos deletéreos del sol que representa un problema de salud pública, de suma importancia. Defensa que logramos con la vestimenta y uso de productos protectores de la piel. Las bacterias, así como otros procariotas, más expuestas a las radiaciones solares han generado plásmidos, que incrementan por medio de un sistema de reparación del ADN, la tolerancia a la UV y otros agentes mutagénicos.

The energy of electromagnetic radiation is derived from the fusion in the sun of four hydrogen nuclei to form a helium nucleus. The sun radiates energy representing the entire electromagnetic spectrum. Light is a form of electromagnetic radiation. All electromagnetic radiation has wave characteristics and travels at the same speed (c: speed of light). But radiations differ in wavelength (λ). Light energy is transmitted not in a continuum stream but only in individual units or photons: E = h c/λ. Short wave light is more energetic than photons of light of longer wavelength. Ultraviolet radiations (UV) (λs 200 - 400 nm) can be classified in UVA (λs 315 - 400 nm.); UVB (λs 280 - 315 nm) and UVC (λs < 280 nm). UVB and UVC are the most significant UV radiations to induce biological responses. Electromagnetic radiations on molecular oxygen lead to several reactive products known as Reactive Oxygen Species (ROS). High O2 content in biological systems promotes ROS synthesis. If ROS are not controlled by endogenous antioxidants, cell redox status is affected and tissue damage is produced ("oxidative stress"). ROS induce lipid peroxidation, protein cross-linking, enzyme inhibition, loss of integrity and function of plasmatic and mitochondrial membranes conducing to inflammation, aging, carcinogenesis and cell death. While infra-red radiations lead to noticeable tissue temperature conducing to severe burns, UVA and UVB undercover react with skin chromophores producing photochemical alterations involved in cellular aging and cancer induction. As UV radiations can reach cellular nucleus, DNA can be damage. Human beings need protection from the damaging sunbeams. This is a very important concern of public health. While humans need to protect their skin with appropriate clothing and/or by use of skin sunblocks of broad spectrum, some bacteria that are extensively exposed to sunlight have developed genomic evolution (plasmid-encoded DNA repair system) which confer protection from the damaging effect of UV radiation.