Qualidade de caqui armazenado sob refrigeração: estádios de maturação, destanização e irradiação ionizante

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Implementação de um sistema eletrônico para medir taxa de fluência de energia de radiação na faixa de radioterapia com sensor piroelétrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ultrastructural evaluation of the radioprotective effect of sodium selenite on submandibular glands in rats

The aim of this study was to evaluate the radioprotector effect of sodium selenite on the ultrastructure of submandibular glands in rats. Fifty-seven male albino Wistar rats were randomized to 4 groups: control, irradiated, sodium selenite and irradiated/sodium selenite. The animals in the sodium selenite and irradiated/sodium selenite groups received intraperitoneal injections of sodium selenite (0.5 mg/kg body weight) 24 h before irradiation. The animals belonging to the irradiated and irradiated/sodium selenite groups were submitted to 15 Gy of gamma radiation in the head and neck region. The submandibular glands were removed at 4, 8, 12, 24, 48 and 72 h after irradiation. The ionizing radiation induced damage to the secretory cells, especially the serous cells, right from the first period. Vacuolization, lysis of cytoplasmic inclusions and nuclear alterations occurred. The sodium selenite group also presented cellular alterations in the study periods, but with less damage compared to that caused by radiation. There was greater similarity between the irradiated/sodium selenite group and the control group than with the other groups treated in all study periods. Despite the alterations observed in the sodium selenite group, sodium selenite presented a radioprotective action on the secretory cells of submandibular glands.

Segundo tumor primário, radioinduzido, em pacientes com neoplasias de próstata, após radioterapia

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Proposal to utilize simplified Swensen protocol in diagnosis of isolated pulmonary nodule

Background: The problem of diagnosing whether a solitary pulmonary nodule is benign or malignant is even greater in developing countries due to a higher prevalence of infectious diseases. These infections generate a large number of patients who are generally asymptomatic and with a pulmonary nodule that cannot be accurately defined as having benign or malignant etiology.Purpose: To verify the percentages of benign versus malignant non-calcified nodules, the length of time after contrast agent injection is spiral computed tomography (CT) most sensitive and specific, and whether three postcontrast phases are necessary.Material and Methods: We studied 23 patients with solitary pulmonary nodules identified on chest radiographs or CT. Spiral scans were obtained with Swensen protocol, but at 3, 4, and 5 min after contrast injection onset. Nodules were classified as benign or malignant by histopathological examination or by an absence or presence of growth after 2 years of follow-up CT.Results: Of the 23 patients studied, 18 (78.2%) showed a final diagnosis of benign and five (21.7%) malignant nodules. Despite the small sample size, we obtained results similar to those of Swensen et al., with 80.0% sensitivity, 55.5% specificity, and 60.8% accuracy. Four minutes gave the greatest mean enhancement in both malignant and benign lesions.Conclusion: Small non-calcified benign nodules were much more frequent than malignant nodules. The best time for dynamic contrast-enhanced CT density analysis was 4 min postcontrast. As well as saving time and money, this simplified Swensen protocol with only precontrast and 4 min postcontrast phases also reduces patient exposure to ionizing radiation.

Chemical composition and lipoxygenase activity in soybeans (Glycine max L. Merr.) submitted to gamma irradiation

Soybeans are an important food due to their functional and nutritional characteristics. However, consumption by western populations is limited by the astringent taste of soybeans and their derivatives which results from the action of lipoxygenase, an enzyme activated during product processing. The aim of this study was to evaluate the effect of gamma irradiation on the chemical composition and specific activity of lipoxygenase in different soybean cultivars. Soybeans were stored in plastic bags and irradiated with doses of 2.5, 5 and 10 kGy. The chemical composition (moisture, protein, lipids, ashes, crude fiber, and carbohydrates) and lipoxygenase specific activity were determined for each sample. Gamma irradiation induced a small increase of protein and lipid content in some soybean cultivars, which did not exceed the highest content of 5% and 26%, respectively, when compared to control. Lipoxygenase specific activity decreased in the three cultivars with increasing gamma irradiation dose. In conclusion, the gamma irradiation doses used are suitable to inactivate part of lipoxygenase while not causing expressive changes in the chemical composition of the cultivars studied. (C) 2014 Elsevier Ltd. All rights reserved.

Datação de Cerâmicas Arqueológicas do Noroeste Paulista pelo Método da Termoluminescência

Pós-graduação em Ciência dos Materiais - FEIS

Avaliação da dose de radiação absorvida em exames radiológicos durante o planejamento radioterápico

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Estudo de um método automatizado para o cálculo da profundidade de visualização dos equipamentos de ultrassonografia

Ultrasound is the term that describes the sound waves with higher frequencies than human hearing. Ultrasound used in medical diagnosis is a modality based on the use of sound energy and the acoustic properties of the various parts of the body to produce images of stationary and moving tissues. However, despite the ease of use and security that this modality offers for not using ionizing radiation, one should ensure the accuracy and optimum performance of the equipment, which results in precise diagnoses. To accomplish that, periodic quality control tests must be performed, which include: physical and mechanical inspection of the equipment, image uniformity, depth of penetration/visualization, accuracy of distances, axial and lateral resolution, dead zone and doppler sensitivity. This work intends to study a computerized method for calculating the depth of penetration of ultrasound, comparing it to the observerdependent method currently used. The images were collected during the quality control tests of ultrasound equipment. The results of the comparison between the visual and computerized methods were not conclusive for selecting the safest methodology for obtaining the depth of visualization

Dosimetria Física e Controle de Qualidade em Radioterapia

Radiotherapy is a multidisciplinary speciality which uses complex equipment and radiation sources for delivery of treatment, using high-energy ionizing radiation to treat cancer at several stages of complexity. Since radiation therapy is a technique which involves a precalculated radiation dose, it shall be established quality assurance programs that provide an efficient and safety treatment. The International Commission on Radiation Units and Measurements (ICRU) report No. 50 has recommended dose uniformity between 5% of the prescribed dose throughout the region of interest. This is one of the most primordial points that justify the importance of a suitable attendance of the equipments quality and performance. For quality control, the medical physicist will be involved with establishing and running a Quality Control Program (QCP). He must adapt or develop the procedures of equipment acceptance and commissioning, besides verifying the use of principles and accepted protocols of national and international reports to assure the correct quality, quantity, and placement of radiation during the performance of a radiological procedure, establishing adequate protocols to ensure accurate patient dosimetry. This present work consists of a description of the activities carried through the Sectors of Radiation Therapy of the Hospital of Clinics of the Campinas State University (Unicamp), particularly in the implementation of the Quality Control Program

Controle de qualidade em radioterapia: dosimetria de fótons em acelerador linear – Mevatron MXT

The treatment of a tumor with ionizing radiation is an ongoing process with well differentiated stages. These ones include the tumor diagnosis and location, the decision on the treatment strategy, the absorbed dose planning and calculation, the treatment administration, the absorbed dose verification and the evaluation of results in short and long terms. The quality of a radiotherapy procedure is closely linked to factors that may be classified as clinical, such as the diagnosis, the tumor location, the treatment strategy chosen and the continuous treatment reassessment; dosimetric or physical, such as the uncertainty in the dose calculation, its optimization and verification, the suitability of the equipment to provide a radiation beam consistent with the treatment planning; finally, others which are related to the practical application of radiotherapy treatment and the handling of the patient. In order to analyze the radiotherapy quality, one should realize that the three aspects (medical, physical or dosimetric and practical application) should be considered in a combined way. This means that numerous actions of the radiotherapists, medical physicists and technicians in radiotherapy should be held jointly and their knowledge level will significantly affect the treatment quality. In this study, the main physical parameters used in dosimetry are defined as well as determined experimentally for a linear accelerator Mevatron - MXT. With this, it is intended to provide recommendations for the physical aspects of Quality Assurance (QA) in the radiotherapy treatments, and these will usually be applied by professionals in Medical Physics. In addition to these instructions, it is recommended that additional texts are prepared to address in detail the clinical aspects of the treatments QA

Método de pontos interiores no planejamento ótimo do tratamento de câncer por radioterapia

The Medical Physics has been developing very fast due to the progress of the technologies and to the increase of the concerns with cure of diseases. One of the Medical Physics main performances at the present time is the use of ionizing radiations for cancer treatment, especially, services as Radiotherapy. The radiotherapy technique uses ionizing radiation with therapeutic end of cancer controls, avoiding your proliferation and it worsens of the patient. For the treatment a radiation bunch is used, with rectangular form, that it passes through the different types of tissues of the patient's body, and depending on the attenuation and of the depth of the fabrics, a great amount of energy is deposited inside in different points of the body. Like this, to plan this treatment type it should be obtained the dimension of the distribution and dose absorption along the volume. For this, it is necessary in the planning of the treatment of the cancer for radiotherapy to build isodose curves, which are lines that represent points of same amount of dose to be deposited in the area to be treated. To aid the construction of the curves of form isodose to reach the best result in the planning of the treatment, in other words, a great planning, providing the maximum of dose in the tumor and saving the healthy and critical organs, it has been using mathematical tools and computational. A plan of cancer treatment for radiotherapy is considered great when all the parameters that involve the treatment, be them physical or biological, they were investigated and adapted individually for the patient. For that, is considered the type and the location of the tumor, worrying about the elimination of the cancer without damaging the healthy tissue of the treated area, mainly the risk organs, which are in general very sensitive to the radiations. This way, the optimization techniques... (Complete abstract click electronic access below)

Uma avaliação do uso do NCRP 151 na realidade brasileira

Medical Physics is an interdisciplinary field that applies concepts and laws of physics in medical practices. Currently, one of its main applications is the use of ionizing radiation in the treatment of oncological diseases. Due to its wide use and highly dangerous, many of radioprotection procedures should be adopted with the objective of protecting human beings from harmful effects of radiation. Thus, you can better enjoy the benefits that the practice can offer. The methodology proposed by the National Council on Radiation Protection 151 (NCRP 151), relates technical information necessary to Structural Shielding Design and Evaluation for Megavoltage X- and Gamma- Ray Radiotherapy Facilities. However, many parameters used to calculate the shield are based on estimates only, and it is an international standard that may not be adequate to the Brazilian reality. Thus, the central idea of this study is the collection of data from the routine of the Radiotherapy Service of the Real e Benemérita Associação Portuguesa de Beneficência, in particular equipment cobalt therapy Theratron 780 (Atomic Energy of Canada Ltd.) and the linear accelerator Varian Clinac 2100C for measurement of workload, number of patients, fields, and dose factors to determine the best use of barrier protection. Furthermore, this work features a profile of radiotherapy treatments carried out closer to the Brazilian reality

Aplicação dos princípios de radioproteção em medicina nuclear

The Nuclear Medicine is a medical specialty which uses different radioisotopes for diagnostic and therapeutic purposes. The isotopes are radioactive elements which are administered in vivo and present distribution to specific organs or cell types. The knowledge of radioactivity and notions related to ionizing radiation allow to contextualize the radiological protection measures to be taken in Nuclear Medicine. So it is possible to minimize unnecessary exposure to patients, the public, and individuals occupationally exposed and the environmental. For this it is necessary to relate the physical and technological bases apply to this mode with the standards established by regulatory agencies, including the CNEN (National Nuclear Energy Commission) and ANVISA (National Agency for Sanitary Vigilance). In this scenario, it is important that the theoretical endorse the activities which are periodically audited for verification of compliance with the standards that aim to radioprotection. One role of the Medical Physicist in these services is, therefore, act as Radiation Protection Supervisor exerting numerous activities and ensuring compliance with these standards. In this context the stage in the area of Nuclear Medicine was developed in many customers of the enterprise Rad Dimenstein & Associados LTDA, among them the hospitals Israelita Albert Einstein (HIAE), Nossa Senhora de Lourdes (HNSL), Santa Paula (HSP), Cruz Azul (CRAZ), Grupo Fleury, among other clinics. Following the routine and then carrying out various activities pertaining to the Medical Physicist in the area, it was noted that the measures and actions are extremely effective and fundamental in terms of radiological protection

Análise do plano de radioproteção em radioterapia

Ionizing radiation is used nowadays in various sectors such as agriculture, industry and medicine. The main specialties of medicine which use radiation are the diagnostic radiology, nuclear medicine and radiotherapy. Radiotherapy is a therapeutic modality that is a well established feature for the treatment of malignant disease or not. However, the inadvertent use of ionizing radiation can produce deleterious effects that result in sequels that compromise the welfare of the people involved. The analysis of radiological protection emphasizes the importance of avoiding inappropriate exhibitions aimed at protecting the health of patients, the professionals involved and the general public. The basic principles of radioprotection are justification, optimization and restriction for individual dosage. The departments of radiotherapy are regulated in accordance with specific technical standards of the National Commission of Nuclear Energy (CNEN), which during the inspection for issue and renewal of the authorization of operation requires the submission of a radioprotection plan, this document that requires great demand of time, and has generated much debate among professionals in medical physics, given the difficulties encountered in their preparation. After examining the radioprotection plan of some radiotherapy services, as suggested in order to guide those responsible for drawing up these plans, especially beginners in the career of the physics of radiation, this paper presents a model plan that is in line radioprotection it requires the Technical Standards of CNEN and can easily be the reality of appropriate services