Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 23
Filter
1.
CES odontol ; 34(1): 52-67, ene.-jun. 2021. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1360261

ABSTRACT

Resumen El uso de rayos X juega un papel esencial en el diagnóstico y planificación de tratamientos dentales. Los avances tecnológicos de los equipos de rayos X han contribuido al mayor uso de este tipo de radiación en la práctica odontológica. Aunque la exposición a la radiación es baja en estos procedimientos, todavía existe un riesgo que debe reducirse al mínimo necesario a fin de obtener una imagen adecuada para el diagnóstico y a la vez evitar efectos nocivos para el paciente y el personal involucrado. Debido al alto y creciente número de radiografías dentales, el hecho de que niños y adolescentes sean el foco de la mayoría de estas, la subestimación de la cantidad de exámenes radiológicos reportados y la supuesta baja conciencia de estudiantes y profesionales de la odontología sobre los peligros del uso indiscriminado de los rayos X, es necesario adoptar medidas de protección radiológica para mitigar los efectos biológicos radioinducidos. Este artículo tiene como objetivo revisar los principios básicos de la radioprotección que deben considerarse en la práctica dental, con el fin de garantizar el menor daño posible a trabajadores ocupacionalmente expuestos, pacientes y miembros del público.


Resumo O uso dos raios X desempenha um papel essencial no diagnóstico e planejamento de tratamentos dentários. O avanço tecnológico nos equipamentos de raios-X tem contribuído para o aumento do uso deste tipo de radiação na prática odontológica. Embora a exposição à radiação seja baixa nestes procedimentos, ela representa um risco e deve ser reduzida ao mínimo valor necessário para se obter a imagem adequada para o diagnóstico, evitando efeitos nocivos ao paciente e ao pessoal envolvido. Devido ao elevado e crescente número de radiografias odontológicas, ao fato de crianças e adolescentes serem o foco de grande parte delas, a subestimação do número de exames radiológicos notificados e a suposta baixa conscientização de estudantes e profissionais da odontologia sobre os perigos dos uso indiscriminado de raios-x, é precisa a adoção de medidas de radioproteção para mitigar o risco de efeitos nocivos radioinduzidos. Este artigo tem como objetivo revisar os princípios básicos da radioproteção a serem considerados na prática odontológica, a fim de garantir o menor prejuízo possível para trabalhadores ocupacionalmente expostos, pacientes e membros do público.


Abstract The use of X-rays plays an essential role in the diagnosis and planning of dental treatments. Technological advances in X-ray equipment have contributed to the increased use of this type of radiation in dental practice. Although radiation exposure is low in these procedures, there is still a risk. The reduction of the risk to the minimum value possible is necessary to obtain an adequate image for the diagnosis and avoiding harmful effects on the patient and the personnel involved. Due to the high and growing number of dental X-rays, the fact that children and adolescents are the focus of most of them, the underestimation of the number of radiological examinations reported and the supposed low awareness of dental students and professionals about the dangers the indiscriminate use of X-rays, it is necessary to adopt radioprotection measures to mitigate the risk of harmful radioinduced effects. This article aims to review the basic principles of radioprotection to be considered in dental radiology, in order to ensure the least possible damage to occupationally exposed workers, patients and public members.

2.
Article in Chinese | WPRIM | ID: wpr-910369

ABSTRACT

As a method for local treatment, radiotherapy plays a key role in the management of tumors. In the past few decades, great progress has been made in radiotherapy technology, with improvements in conformity, homogeneity, and radiotherapy efficiency, and the results are encouraging. Nevertheless, the maximum tolerated dose of normal tissue has limited the further increase in radiotherapy dose in the tumor area. If radiation-induced toxicities can be reduced, a higher radiotherapy dose can be delivered to tumor tissue, so as to achieve a better treatment response. In recent years, the unique FLASH effect of ultra-high-dose-rate radiotherapy (FLASH-RT) is capable of maintaining a consistent tumor response whilst reducing radiation-induced toxicities in normal tissue, and therefore, FLASH-RT has become a research hotspot in the field of radiotherapy across the world. At present, some scholars tend to explain the FLASH effect using the theory of acute oxygen depletion, but the protective effect of FLASH-RT on normal tissue remains to be clarified. In addition, preliminary clinical studies have been conducted for FLASH-RT, and the results are promising. Based on existing evidence, this article elaborates on the research advances in FLASH-RT in the treatment of malignant tumor, so as to provide a reference for the translation and application of this new technique.

3.
Article in Chinese | WPRIM | ID: wpr-755080

ABSTRACT

Objective To investigate the radiation induced pulmonary fibrosis with a dose-response mouse model, based on the CT image changes of pulmonary fibrosis.Methods Female C57BL6 mice aged 8-10 weeks were randomly divided into 20 Gy or escalated doses of X-ray whole thoracic irradiation ( WTI) groups. CT scan was performed at different time points before and after radiation. The average lung density and lung volume changes were obtained by three-dimensional segmentation algorithm. After gene chip and pathological validation, the parameters of CT scan were subject to the establishment of logistic regression model. Results At the endpoint of 24 weeks post-irradiation, the lung density in the 20 Gy irradiation group was (-289.81± 12.06) HU, significantly increased compared with (-377.97± 6.24) HU in the control group ( P<0.001) . The lung volume was ( 0.66±0.01) cm3 in the control group, significantly larger than ( 0.44±0.03) cm3 in the irradiated mice ( P<0.001) . The results of quantitative imaging analysis were in accordance with the findings of HE and Mason staining, which were positively correlated with the fibrosis-related biomarkers at the transcriptional level ( all R2=0.75, all P<0.001) . The ED50 for increased lung density was found to be ( 13.64± 0.14) Gy ( R2=0.99, P<0.001) and ( 16.17± 4.36) Gy ( R2=0.89, P<0.001) for decreased lung volume according to the logistic regression model. Conclusions Quantitative CT measurement of lung density and volume are reliable imaging parameters to evaluate the degree of radiation-induced pulmonary fibrosis in mouse models. The dose-response mouse models with pulmonary fibrosis changes can provide experimental basis for comparative analysis of high-dose hypofractioned irradiation-and half-lung irradiation-induced pulmonary fibrosis.

4.
Article in Chinese | WPRIM | ID: wpr-755013

ABSTRACT

Brachythrapy is a technique to implant radioactive isotype into or near tumors.The obvious properties of brachytherapy are a very high dose distribution of center,and rapid dose attenuation with the increasing of distance.Brachytherapy generally includes three major categories:low dose rate,high dose rate and pulse dose rate.The most significant clinical value of brachytherapy is that it could create dose distribution to tumor tissues,but decreased radiation injury of normal tissues close to tumor.The development of the clinical brachytherapy technique is always involved in the radiobiological characteristics.The basic concepts involving clinical brachytherapy radiobiology mainly includes:dose-rate effect,repair of radiation injury,re-oxygenation,cell cycle redistribution and repopulation.An amount of translational medical approach is needed to guide the application of clinical brachytherapy by exploring the interaction between brachytherapy radiobiology and clinical brachytherapy effect,as well as taking advantage of brachytherapy radiobiological characteristics.The ultimate goal is to improve tumor local control rate,reduce the occurrence of adverse reactions,and improve patients' overall survival.

5.
Article in Chinese | WPRIM | ID: wpr-755010

ABSTRACT

With the development of modern computing technology and medical physics,radiotherapy has made great progress.The theoretical basis of radiobiology seems to lag behind the clinical application of radiotherapy,which hampers the further improvement of treatment efficacy and the optimization of treatment modality.In this paper,some emerging challenges of precision radiotherapy technology to the traditional theory of radiobiology,such as radiosensitivity,dose-response curve and survival curve,linear-quadratic model,4Rs theory,as well as the interaction between cancer and microenvironment,radiation-induced second primary cancers (RISPC),will be discussed.The interplay between precision radiotherapy and traditional radiobiology theories will be addressed with the aim to potentially solve some of the challenging problems.

6.
Article in Chinese | WPRIM | ID: wpr-734361

ABSTRACT

This paper made a detailed interpretation about the radiobiology-related contents in the ICRU report No.89,aiming to provide reference to resolve the problems related to radiobiology for the colleagues occupied in the brachytherapy for cervical cancer.

7.
Article in Chinese | WPRIM | ID: wpr-807148

ABSTRACT

Proton is formed after hydrogen atom loses an electron with a positive charge of particle (H+ ). After the proton is accelerated, it possesses significant advantages in terms of the distribution of physical dose compared with the photon. Currently, proton radiation has captivated extensive attention and has been actively applied in clinical practice. Nevertheless, due to the small amount of proton facilities and lack of clinical trials, the proton therapy, especially the radiobiological characteristics and biological effect of photon radiotherapy has been poorly understood. In this article, these issues were summarized as below.

8.
Article in Chinese | WPRIM | ID: wpr-708280

ABSTRACT

Stereotactic body radiotherapy ( SBRT) has been gradually proven to be effective in treating multiple solid tumors. Along with the development of image-guided radiotherapy (IGRT) system and radiotherapy,SBRT can form a high-dose region in the target area,whereas the dose gradient outside the target area declines rapidly. It not only delivers large-dose irradiation to the tumors,but also protects the surrounding normal tissues as possible,thereby implementing safe" big fractionated radiotherapy" .At present, regular understanding of the radiobiology underlying SBRT is still lacking. Multiple issues, such as applicability of linear quadratic ( LQ) model, weakening of re-oxygenation, additional cell killing effect different from conventional fractionated radiotherapy and immune enhancement effect are still controversial. In this article,the above controversial hotspots were discussed and analyzed,aiming to deepen the understanding of the radiobiological characteristics of SBRT and contribute to promoting the application of SBRT in clinical practice.

9.
Radiation Oncology Journal ; : 172-181, 2018.
Article in English | WPRIM | ID: wpr-741955

ABSTRACT

Successful anticancer strategies require a differential response between tumor and normal tissue (i.e., a therapeutic ratio). In fact, improving the effectiveness of a cancer therapeutic is of no clinical value in the absence of a significant increase in the differential response between tumor and normal tissue. Although radiation dose escalation with the use of intensity modulated radiation therapy has permitted the maximum tolerable dose for most locally advanced cancers, improvements in tumor control without damaging normal adjacent tissues are needed. As a means of increasing the therapeutic ratio, several new approaches are under development. Drugs targeting signal transduction pathways in cancer progression and more recently, immunotherapeutics targeting specific immune cell subsets have entered the clinic with promising early results. Radiobiological research is underway to address pressing questions as to the dose per fraction, irradiated tumor volume and time sequence of the drug administration. To exploit these exciting novel strategies, a better understanding is needed of the cellular and molecular pathways responsible for both cancer and normal tissue and organ response, including the role of radiation-induced accelerated senescence. This review will highlight the current understanding of promising biologically targeted therapies to enhance the radiation therapeutic ratio.


Subject(s)
Aging , Radiobiology , Radioimmunotherapy , Signal Transduction , Tumor Burden
10.
Arq. odontol ; 52(3): 130-135, jul.-set. 2016. tab
Article in Portuguese | LILACS, BBO | ID: biblio-832133

ABSTRACT

Objetivo: Avaliar o conhecimento de cirurgiões-dentistas da cidade de Patos-PB acerca da biossegurança em radiologia odontológica e métodos de proteção utilizados. Métodos: Foi utilizada uma abordagem indutiva com procedimento estatístico descritivo e técnica de documentação direta através da pesquisa de campo, utilizando o formulário como instrumento. Participaram do estudo 50 cirurgiões-dentistas que trabalhavam em consultórios particulares com aparelho de raios X intraoral na cidade de Patos-PB. Após a assinatura do Termo de Consentimento Livre e Esclarecido pelos profissionais, foram aplicados questionários para avaliação do conhecimento dos mesmos sobre biossegurança em radiologia e práticas de proteção utilizadas. Os dados foram tabulados e foi feita análise descritiva das variáveis qualitativas pelas medidas de proporção, frequências e porcentagens. Resultados: Observou-se que todos os profissionais mostraram preocupação em relação à radioproteção e que buscavam realizar os exames radiográficos seguindo os princípios de cada técnica radiográfica a fim de se evitar a repetição das mesmas. Para proteção do paciente, a maioria relatou utilizar avental de chumbo, incluindo protetor de tireóide, além de reduzir o tempo de exposição. Acerca da proteção própria, a maior parte afirmou possuir paredes com revestimento de chumbo. Conclusão: Observouse que a maioria dos profissionais tem conscientização acerca dos aspectos de radioproteção, contudo, alguns cirurgiões-dentistas ainda desconhecem os mesmos e não praticam a biossegurança em radiologia, colocando em risco sua própria saúde e a dos pacientes.(AU)


Aim: To assess the knowledge of dentists in the city of Patos, PB, Brazil, about biosafety in radiology and applied protection methods. Methods: This study involved an inductive approach with a descriptivestatistical procedure and a research technique for direct documentation in the field, using a questionnaire as the main instrument. This study included 50 dentists who work in private practices with intraoral X-ray units in Patos, PB. After the professionals had signed the Free and Informed Consent Form, questionnaires were applied to evaluate the dentists' knowledge about biosafety in radiology and their protection practices. The data were tabulated, and a descriptive analysis was performed regarding the qualitative variables measured by proportion, frequencies, and percentages. Results: It was observed that all of the staff were concerned about their own radioprotection and that they sought to comply with the principles of each radiographic technique in order to avoid repeating radiographs. For patient protection, the majority reported using lead aprons, including a thyroid shield, in addition to reducing exposure time. Regarding their own protection, most facilities have walls with lead casing. Conclusion: It was observed that most professionals are aware of the aspects of radiological protection; however, some are still unfamiliar with these procedures and do not practice biosafety in radiology, putting their own health and that of their patients at risk.(AU)


Subject(s)
Dentists , Radiation Protection , Radiology , Health Knowledge, Attitudes, Practice , Radiobiology
11.
China Pharmacist ; (12): 624-630, 2016.
Article in Chinese | WPRIM | ID: wpr-490902

ABSTRACT

Objective:To investigate the radiosensitizing effect of three flavonoids on ovarian cancer SKOV3 cells under hypoxia. Methods:The SKOV3 cells were divided into normoxic group and hypoxic group. The hypoxic SKOV3 cellular model in vitro was es-tablished and tested by measuring the expression profile of HIF-1αprotein in SKOV3 cells. Colony-forming assay was used to detect the radiosensitivity of normoxic and hypoxic SKOV3 cells. The cytotoxicity and radiosensitizing effects of flavonoids were evaluated on the basis of cell death and MTT assay. Results:The Western blot results showed that the gray intensity ratio of HIF-1α/β-Actin in hypoxia group was significantly higher than that in normoxia group (1. 068>0. 117). Radiosensitivity of hypoxic SKOV3 cells in hypoxia group was significantly lower than that in normoxia group. The survival rate of SKOV3 cells was decreased with the increase of concentration. When the concentration was increased, D0 and Dqin chrysin group and quercetin group were significantly decreased (P0. 05). The overall radiobiological parameters of hypoxia group were higher than those of normoxia group. Conclusion: Hypoxia can induce the expression of HIF-1α in SKOV3 cells, which results in the decrease of radiosensitivity. Chrysin and quercetin can enhance the radiosensitivity of SKOV3 cells, and the enhancement is significant under hypoxia, while breviscapine is without such effect. The radiosensitizing effect may be achieved by the level decrease of HIF-1α in SKOV3 cells and inhibition of DNA damage repair.

12.
Article in English | WPRIM | ID: wpr-66008

ABSTRACT

Inevitable human exposure to ionizing radiation from man-made sources has been increased with the proceeding of human civilization and consequently public concerns focus on the possible risk to human health. Moreover, Fukushima nuclear power plant accidents after the 2011 East-Japan earthquake and tsunami has brought the great fear and anxiety for the exposure of radiation at low levels, even much lower levels similar to natural background. Health effects of low dose radiation less than 100 mSv have been debated whether they are beneficial or detrimental because sample sizes were not large enough to allow epidemiological detection of excess effects and there was lack of consistency among the available experimental data. We have reviewed an extensive literature on the low dose radiation effects in both radiation biology and epidemiology, and highlighted some of the controversies therein. This article could provide a reasonable view of utilizing radiation for human life and responding to the public questions about radiation risk. In addition, it suggests the necessity of integrated studies of radiobiology and epidemiology at the national level in order to collect more systematic and profound information about health effects of low dose radiation.


Subject(s)
DNA Damage/drug effects , Environmental Exposure , Humans , Leukemia/epidemiology , Neoplasms, Radiation-Induced/epidemiology , Radiation Dosage , Radiation Tolerance , Radiation, Ionizing , Radioactive Hazard Release , Risk
13.
Article in English | WPRIM | ID: wpr-66000

ABSTRACT

Radiotherapy, which is one of three major cancer treatment methods in modern medicine, has continued to develop for a long period, more than a century. The development of radiotherapy means allowing the administration of higher doses to tumors to improve tumor control rates while minimizing the radiation doses absorbed by surrounding normal tissues through which radiation passes for administration to tumors, thereby reducing or removing the incidence of side effects. Such development of radiotherapy was accomplished by the development of clinical radiation oncology, the development of computers and machine engineering, the introduction of cutting-edge imaging technology, a deepened understanding of biological studies on the effects of radiation on human bodies, and the development of quality assurance (QA) programs in medical physics. The development of radiotherapy over the last two decades has been quite dazzling. Due to continuous improvements in cancer treatment, the average five-year survival rate of cancer patients has been close to 70%. The increases in cancer patients' complete cure rates and survival periods are making patients' quality of life during or after treatment a vitally important issue. Radiotherapy is implemented in approximately 1/3 to 2/3s of all cancer patients; and has improved the quality of life of cancer patients in the present age. Over the last century, as a noninvasive treatment, radiotherapy has unceasingly enhanced complete tumor cure rates and the side effects of radiotherapy have been gradually decreasing, resulting in a tremendous improvement in the quality of life of cancer patients.


Subject(s)
Humans , Magnetic Resonance Imaging , Neoplasms/radiotherapy , Quality Assurance, Health Care , Quality of Life , Radiation Protection , Tomography, X-Ray Computed
14.
Neumol. pediátr. (En línea) ; 10(2): 54-57, abr. 2015. tab, graf
Article in Spanish | LILACS | ID: lil-773902

ABSTRACT

The advance of medical imaging technology has led to an increase in the medical radiation exposure, especially derived from computed tomography (CT). Recent studies confirm a small but significant increase of cancer cases induced by CT radiation. Children are markedly more sensitive to radiation than adults and in addition, their life expectancy is longer, so we must use all resources to optimize and reduce the exposure dose using the ALARA concept. CT is an important diagnostic tool in medical practice and its benefits far outweigh the costs of radiation if the indication is properly justified.


El avance tecnológico de las imágenes para evaluación de enfermedades ha llevado a un aumento considerable de la radiación de origen médica, principalmente la proveniente de la tomografía computada (TC). Estudios recientes confirman un pequeño pero significativo incremento de casos de cáncer inducidos por radiación generada por la TC. Siendo los niños reconocidamente más sensibles a la radiación que los adultos y sumado a su mayor expectativa de vida, es que debemos usar todos los recursos para optimizar y reducir la dosis de exposición aplicando el concepto de ALARA. La TC es una herramienta diagnóstica importantísima en la práctica médica, y sus beneficios superan ampliamente los costos de la radiación si su indicación está adecuadamente justificada.


Subject(s)
Humans , Child , Neoplasms, Radiation-Induced/etiology , Tomography, X-Ray Computed/adverse effects , Radiation Dosage , Neoplasms, Radiation-Induced/prevention & control , Risk Assessment , Radiography/adverse effects
15.
Radiation Oncology Journal ; : 265-275, 2015.
Article in English | WPRIM | ID: wpr-70167

ABSTRACT

Despite the increasing use of stereotactic body radiation therapy (SBRT) and stereotactic radiation surgery (SRS) in recent years, the biological base of these high-dose hypo-fractionated radiotherapy modalities has been elusive. Given that most human tumors contain radioresistant hypoxic tumor cells, the radiobiological principles for the conventional multiple-fractionated radiotherapy cannot account for the high efficacy of SBRT and SRS. Recent emerging evidence strongly indicates that SBRT and SRS not only directly kill tumor cells, but also destroy the tumor vascular beds, thereby deteriorating intratumor microenvironment leading to indirect tumor cell death. Furthermore, indications are that the massive release of tumor antigens from the tumor cells directly and indirectly killed by SBRT and SRS stimulate anti-tumor immunity, thereby suppressing recurrence and metastatic tumor growth. The reoxygenation, repair, repopulation, and redistribution, which are important components in the response of tumors to conventional fractionated radiotherapy, play relatively little role in SBRT and SRS. The linear-quadratic model, which accounts for only direct cell death has been suggested to overestimate the cell death by high dose per fraction irradiation. However, the model may in some clinical cases incidentally do not overestimate total cell death because high-dose irradiation causes additional cell death through indirect mechanisms. For the improvement of the efficacy of SBRT and SRS, further investigation is warranted to gain detailed insights into the mechanisms underlying the SBRT and SRS.


Subject(s)
Antigens, Neoplasm , Cell Death , Humans , Radiobiology , Radiotherapy , Recurrence
16.
Acta méd. costarric ; 55(3): 110-117, jul.-sep. 2013. ilus, tab
Article in Spanish | LILACS | ID: lil-700688

ABSTRACT

La biodosimetría citogenética se aplica en la evaluación médica de las personas involucradas en situaciones radiológicas anormales, con el fin de evaluar las dosis recibidas, el peligro inminente para la salud y aplicar los tratamientos médicos más adecuados. Además, contribuye al esclarecimiento de sucesos cuando existen dudas respecto a los resultados de la dosimetría física por dosímetros defectuosos, no calibrados o ausentes. Es el método más preciso de dosimetría biológica, ya que existe una relación matemática que permite calcular la dosis, establecer el grado de homogenidad de la exposición y, en caso de exposiciones no homogéneas, establecer la fracción del cuerpo irradiada y la dosis que recibió esa fracción mediante la cuantificación del número y tipos de aberraciones cromos¢micas y de micronúcleos y su distribución en los linfocitos de la sangre periférica. Para este análisis se establecen las relaciones dosis-efecto y un sistema automatizado para el cálculo de las dosis de radiación recibidas. Actualmente se está desarrollando un proyecto conjunto Universidad de Costa Rica-Hospital San Juan de Dios, con el objetivo de explorar los efectos cromosómicos de la radiación, en pacientes expuestos por razones el objetivo de explorar los efectos cromosómicos de la radiación, en pacientes expuestos por razones terapéuticas y atendidos en este hospital. De igual modo, se hará la curva de calibración dosis-respuesta in vitro para rayos gama y se validar  mediante la intercomparación con el Laboratorio de Dosimetría Citogenética de Centro para la Protección e Higiene de las Radiaciones de Cuba...


Subject(s)
Humans , Cytogenetics , Radioactive Hazard Release/classification , Radiation Exposure , Radiation, Ionizing , Radiobiology , Radiometry
17.
Univ. odontol ; 30(67): 111-129, jul.-dic. 2012. ilus, tab
Article in Spanish | LILACS | ID: lil-673833

ABSTRACT

Objetivo: Presentar los principales conceptos de radiobiología, radioterapia en cavidadoral y complicaciones asociadas, para llevar a cabo acciones seguras de tipo preventivo yterapéutico por parte del profesional o del equipo tratante. Método: La revisión se llevó acabo en diferentes bases de datos y revistas acerca del manejo odontológico de pacientessometidos a radioterapia. Resultados: Actualmente, el tratamiento para el cáncer tiene unenfoque multidisciplinario, en el cual participan distintos profesionales de la salud (incluidoel odontólogo) en las fases de diagnóstico, tratamiento específico mediante extirpaciónquirúrgica, tratamiento citotóxico con quimioterapia y radiaciones ionizantes, y rehabilitación.La radioterapia trae consigo complicaciones producto de la interacción de las radiacionesionizantes con el organismo: efectos de tipo físico, químico y biológico, debido a lainteracción entre las partículas cargadas y los átomos del tejido irradiado. Adicionalmente,se llevan a cabo reacciones enzimáticas que reparan la mayoría de las lesiones radioinducidas,como daños en el ADN, y los principales efectos radiobiológicos negativos o adversos.En la cavidad oral se presentan complicaciones de tipo agudo como mucositis, xerostomíay riesgo de infección; al igual que reacciones tardías como alteración en la vascularizaciónde hueso y mucosa, daño en glándulas salivares, reducción celular en el tejido conectivo yriesgo de incremento en la síntesis de colágeno, lo que resulta en fibrosis y produce tejidoshipovasculares, hipocelulares e hipóxicos, que afectan al hueso, pues reduce su capacidadde remodelación e incrementa su riesgo de infección y osteorradionecrosis...


Objective: To introduces the main concepts in radiobiology, radiotherapy in the oral cavity,and complications associated with them, in order to carry out preventive and curativeactions safely by the health professional and team. Method: The review was performed inseveral databases and journals on the dental care of patients undergoing radiotherapy. Results:Currently, treatment for cancer is carried out through a multidisciplinary approach withdifferent health professionals (including dentists) participating to determine its diagnosis,specific treatment through surgical removal, cytotoxic treatment with chemotherapy and/or ionizing radiation, and rehabilitation. Radiotherapy produces complications as a reactionbetween the ionizing radiation and the body: Physical, chemical and biological effects due tointeractions between the charged particles and the atoms of the irradiated tissue; in addition,enzymatic reactions take place to repair most of the radioinduced lesions, like damagein the DNA, the main negative or adverse radiobiological effects. In the oral cavity, there areacute reactions such as mucositis, xerostomia and risk of infection, as well as late reactionssuch as alterations of bone and mucose vascularization, saliva gland damage, cell reductionin connective tissue, and risk of collagen synthesis increase, which results in fibrosis andhypovascular, hypocellular and hypoxic tissues that affect bones because its remodelingcapacity is diminished and the risk of infection and osteor adionecrosis is incr eased...


Subject(s)
Brachytherapy/methods , Mouth Neoplasms , Mucositis , Mouth Neoplasms/drug therapy , Osteonecrosis , Radiotherapy, Intensity-Modulated , Xerostomia
18.
Radiol. bras ; 44(5): 297-300, set.-out. 2011. tab
Article in Portuguese | LILACS | ID: lil-612931

ABSTRACT

OBJETIVO: Avaliar os efeitos da radiação ionizante sobre o paladar, em pacientes que foram submetidos a radioterapia na região de cabeça e pescoço. MATERIAIS E MÉTODOS: Foram selecionados 20 pacientes que possuíam diagnóstico de tumor na região de cabeça e pescoço, que iniciaram tratamento no Setor de Radioterapia da Santa Casa de Misericórdia de Belo Horizonte, MG, Brasil. Para testes do paladar, foram manipuladas quatro soluções (salgada - NaCl; doce - sacarose; azeda - ácido cítrico; amarga - ureia) em três concentrações diferentes (fraca, média e forte), administradas por meio de conta-gotas, três gotas de cada solução de maneira aleatória, respeitando a ordem das concentrações fracas, médias e fortes. Após a aplicação de cada solução, o paciente relatava o sabor que sentia. O procedimento foi realizado semanalmente durante as três primeiras semanas de radioterapia. RESULTADOS: Foi observada diferença estatisticamente significante na perda do paladar dos pacientes em tratamento radioterápico, quando se compararam a 1ª e 4ª semanas de tratamento na solução salgada, nas três concentrações, na solução doce nas concentrações fracas e médias e nas soluções azedas e amargas, apenas quando se testaram as concentrações fracas. CONCLUSÃO: A radiação ionizante altera o paladar de pacientes submetidos a radioterapia de cabeça e pescoço.


OBJECTIVE: To evaluate the effects of ionizing radiation on the taste function in patients submitted to radiotherapy in the head and neck region. MATERIALS AND METHODS: Twenty patients diagnosed with head and neck tumors and undergoing treatment in the Division of Radiotherapy at Santa Casa de Misericórdia de Belo Horizonte, MG, Brazil, were selected. For their taste function testing, four solutions were manipulated with salt (NaCl), sugar (sucrose), citric acid (for acidity), and urea (for bitterness), at three different (low, medium and high) concentrations. Weekly tests were performed during the first three weeks of radiotherapy, with random administration of the solutions (three drops each) respecting the order of their concentration levels (low, medium and high). After the application of each solution, the patient reported which flavor he/she tasted. RESULTS: A statistically significant difference was observed in the loss of taste function as the results in the 1st and 4th weeks of treatment were compared, with salty solution at the three concentration levels, with the sweet solution at low and medium concentrations, and with the sour and bitter solutions, only at low concentration. CONCLUSION: Ionizing radiation alters the taste function of patients submitted to head and neck radiotherapy.


Subject(s)
Humans , Adolescent , Young Adult , Middle Aged , Ageusia , Ageusia/complications , Head and Neck Neoplasms/radiotherapy , Head and Neck Neoplasms , Medical History Taking , Radiation, Ionizing , Radiobiology , Radiotherapy/adverse effects , Taste
19.
Article in Chinese | WPRIM | ID: wpr-388966

ABSTRACT

Objective To detect specific cell killing effect of radiation combined with horseradish peroxidase (HRP)/indole-3-acetic (IAA) suicide gene therapy controlled by a novel radio-inducible and cancer-specific chimeric gene promoter in lung cancer. Methods We constructed a plasmid expressing HRP enzyme under the control of chimeric human telomerase reverse transcriptase (hTERT) promoter carrying 6 CArG elements, a plasmid expressing HRP enzyme under the control of hTERT promoter carrying single CArG element, and two control plasmids, which named pE6-hTERT-HRP, phTERT-HRP, pControl-HRP, and pControl-luc, respectively. After radiation, the proliferation inhibition and apoptosis induction effect of each type of plasmid in lung cancer cells (A549, SPC-A1) and normal lung cells (hEL) was detected by cell counting and Annexin V-FITC staining. The change of radiosensitivity of lung cancer cells with plasmid system was also detected by clonogenic assays. Results After a single dose radiation of 6 Gy,the average proliferation inhibition rates of pE6-hTERT-HRP, phTERT-HRP, pControl-HRP, and pControl-luc systems were 72. 92% ,40.60% , 51.00% and 25.19% (F= 67.31 , P< 0.01) in A549 cells ,64.63%,30.02%,48.23% and 23.16% (F=64.94, P< 0.01) in SPC-A1 cells, and 20.81%,18.05%, 44.20% and 18.32% (F=52. 19,P<0.01) in normal hEL cells, respectively. The average early apoptosis rates of these four plasmid systems were 36. 63%, 22. 30%, 24. 33% and 12. 53% (F =50. 99,P <0. 01) in A549 cells, 33.73%, 17. 37%, 22. 43% and 11.20% (F = 20. 76, P < 0. 01) in SPC-A1 cells, and 13.53 %, 12. 5%, 21.93% and 12. 16% (F = 15. 08, P < 0. 01) in normal hEL cells,respectively. The sensitizing enhancement ratios of the four plasmid systems were 3.45, 2. 29, 3.05 and 1.21 in A549 cells, while 2. 68, 2. 15, 3.05 and 1.21 in SPC-A1 cells, respectively. Conclusions The new suicide gene system controlled by chimeric promoter may provide a novel therapeutic modality for lung cancer.

20.
ROBRAC ; 19(51)2010.
Article in Portuguese | LILACS-Express | LILACS | ID: lil-604910

ABSTRACT

Objetivo: Realizar uma pesquisa em consultórios odontológicos na cidade de São José do Rio Preto - SP sobre conhecimento e atitudes dos profissionais sobre proteção radiológica e comparar os dados com as recomendações da Portaria 453 do Ministério da Saúde. Material e Método: Cento e cinqüenta consultórios odontológicos foram visitados e foi aplicado um questionário. Resultados: Observou-se que 26% dos entrevistados não conheciam a lei, 23% não avaliavam radiografias existentes do paciente, 21% não usavam vestimenta plumbífera nos pacientes, 49% não usavam posicionadores de filmes, 58% ainda utilizavam processamento visual; 93% utilizavam filme E ou F, entretanto a média de tempo de exposição foi 0.5 segundo, 14% dos equipamentos possuíam cone localizador e 83% seletor de tempo manual, 17% dos dentistas não se protegiam durante a exposição do paciente e 64% ainda utilizavam disparador com retardo. Conclusão: Há falta de conhecimento sobre proteção radiológica; um programa educacional em Radiologia pode produzir mudanças nas atitudes dos profissionais em relação ao uso da radiação ionizante.


Objective: To perform a research in dental offices in the city of São José do Rio Preto-SP about the practitioners' knowledge and attitudes related to radiological protection and compare the data with the recommendations of Ordinance 453 of the Health Ministry. Material and Methods: One hundred and fifty dental offices were visited and a questionnaire was applied. Results: Was observed that 26% of the interviewed did not know the law, 23% did not evaluate the patient's existing radiographs, 21% did not wear lead clothing in patients, 49% did not use film positioners, 58% still used visual processing, 93% used film E or F, however the average exposure time was 0.5 second, 14% of the equipment had locator cone and 83% had manual time selector, 17% of dentists do not protect themselves during the patient's exposure and 64% still used delayed trigger. Conclusion: There Atitudes dos Cirurgiões-Dentistas em Relação à Proteção Radiológica, de Acordo com a Lei Brasileira Pesquisa Rev Odontol Bras Central 2010;19(51) 305 is a lack of knowledge about radiological protection. An educational program in Radiology can produce changes in attitudes of professionals regarding the use of ionizing radiation.

SELECTION OF CITATIONS
SEARCH DETAIL