Дисертації з теми "Gel dosimeters"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Gel dosimeters".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Wong, Christopher James, and chrisjwong@yahoo com au. "High Resolution Polymer Gel Dosimetry for Small and Micro Field Dosimetry, and Development of Innovative Polymer Gel Dosimeters." RMIT University. Medical Sciences, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20091002.161512.
Повний текст джерелаTrapp, Jamie Vincent. "Imaging and radiation interactions of polymer gel dosimeters." Thesis, Queensland University of Technology, 2003. https://eprints.qut.edu.au/15904/1/Jamie_Trapp_Thesis.pdf.
Повний текст джерелаTrapp, Jamie Vincent. "Imaging And Radiation Interactions Of Polymer Gel Dosimeters." Queensland University of Technology, 2003. http://eprints.qut.edu.au/15904/.
Повний текст джерелаSedaghat, Mahbod. "A study on radiochemical errors in polymer gel dosimeters." Thèse, Université de Sherbrooke, 2012. http://hdl.handle.net/11143/6252.
Повний текст джерелаHurley, Christopher Anthony. "The development of normoxic polymer gel dosimetry using high resolution MRI." Thesis, Queensland University of Technology, 2006. https://eprints.qut.edu.au/16442/1/Christopher_Hurley_Thesis.pdf.
Повний текст джерелаHurley, Christopher Anthony. "The development of normoxic polymer gel dosimetry using high resolution MRI." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16442/.
Повний текст джерелаTudela, Diego Renan Giglioti. "Estudo da luminescência de cristais de quartzo naturais e artificiais crescidos pelo método sol-gel." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-08032019-090623/.
Повний текст джерелаThis work was divided into two major parts, the first one related to the study of the luminescence of four Brazilian natural quartz specimens (green, hyaline, pink and blue) and the second one deals with the confection and characterization of synthetic samples, based on SiO2 structure, obtained by means of sol-gel method to environmental ionizing radiation dosimetry. Through Instrumental Neutron Activation Analysis (INAA) and Total Reflection X-ray Fluorescence (TXRF), the main impurities in major, minor and trace concentrations were determined quantitative and qualitatively respectively. The green and blue specimens presented the highest amounts of impurities, including metals and rare earth elements, whereas hyaline and pink are practically pure. Their TL emissions were distinct, in terms of intensity and peak position. OSL dose recovery tests, using multiple (MAR) and single aliquots regeneration (SAR) dose protocols were performed and the green specimen was the only one which presented satisfactory results in these tests, followed by blue. The hyaline and pink crystals showed saturation and growth curve out of linearity, where the first one showed the effect of phototransference for most SAR analysis. As green and hyaline crystals presented opposite results, in terms of impurities quantities and luminescent emissions, a high temperature (1600 °C) heat treatment was performed to observe the effect of the phase change (cristobalite) on its luminescent emissions. Theoretical adjustments of the CW-OSL, LM-OSL and TL emission curves showed that they follow the theoretical model of general order kinetics. In the second part of this work, 32 artificial samples of the high temperature polymorph of the quartz, cristobalite, were synthesized with different amounts and types of dopants, based on impurities determined in green quartz, making use of two heating rates in the calcinations (3 and 15 °C/min). This part of the work had as purpose the study of the effect of Fe in the luminescent emission of the synthetic samples, the reproduction of one of the natural samples and production and characterization of dosimeters for environmental ionizing radiation. The use of the two heating rates in TL emission, in general, did not play a determining role in the intensity of the high temperature peaks. In the OSL, it was observed that samples calcined with higher heating rate temperature showed higher response to dose. The Fe as a dopant in greater quantities acted as a quencher of luminescence both in TL and OSL. A sample with qualitative characteristics similar to the green quartz, in the cristobalite phase, was obtained with relative success using as dopants all the twelve main impurities acquired for this project. Four samples were synthesized with different types and amounts of dopants for application in ionizing radiation dosimetry. Only one of these showed a linear response to radiation doses using thermal stimulation (TL), with a minimum detectable dose (MDD) of 172 µGy. Using optical stimulation (OSL), two samples showed linear behavior with radiation doses, in which MDD values of ~440 µGy and 405 µGy were obtained.
Mizuno, Erick Yukio. "Desenvolvimento e caracterização de um gel de alanina para aplicação na medida da distribuição da dose de radiação usando a técnica de espectrofotometria." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-16052012-110041/.
Повний текст джерелаThe aim of this work is to develop a DL-Alanine, Fe-ll based gel dosimeter to be applied in the dosimetry of the Co-60 gamma-radiation fields in the dose range of radiation therapy procedures. The aminoacid DL-Alanine is dissolved in an acid solution containing the Fe-ll and added to the gel. A series of essays was performed with different chemicals and different procedures were made to evaluate the behavior of the obtained dosimetric gel as function of the time. The absorption spectra, before and after the irradiation, present maximum in 457 nm and 588 nm, respectively. These two peaks correspond to absorption wavelengths of the chemical species Fe-ll and Fe-lll, respectively, both species being in equilibrium. With the irradiation, the formation of the radicals that oxide the Fe-ll into Fe-lll occurs, altering the chemical balance of both species - hence the increase of the Fe-lll - and causing the gel to change its tonality, in such a way that it is possible to determine the absorved dose. In the analysis of the spectra and respective dose-response curves it was observed that the dosimetric gel shows linearity in dose range of 0.5 to 40 Gy. From the obtained linearity results, stability and lower detectable dose - 0,3 Gy - it is possible to conclude that the present DL-Alanine, Fe-ll based dosimetric gel presents an excellent potential to the application to which it is proposed, namely, the determination of the dose fields in radiation therapy and its future application as a standard in the determination of these fields, in 3D, using the Magnetic Resonance Imaging.
CAPELETI, FELIPE F. "Dosimetria em tomografia computadorizada e avaliação do perfil de dose empregando dosímetro fricke gel e a técnica de imageamento por ressonância magnética." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11789.
Повний текст джерелаMade available in DSpace on 2014-11-10T10:43:39Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
CAVINATO, CHRISTIANNE C. "Padronizacao do metodo de dosimetria fricke gel e avaliacao tridimensional de dose empregando a tecnica de imageamento por ressonancia magnetica." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9406.
Повний текст джерелаMade available in DSpace on 2014-10-09T14:04:11Z (GMT). No. of bitstreams: 0
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
MIZUNO, ERICK Y. "Desenvolvimento e caracterização de um gel alanima para aplicação na medida da distribuição da dose de radiação usando a técnica de espectrofotometria." reponame:Repositório Institucional do IPEN, 2007. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11571.
Повний текст джерелаMade available in DSpace on 2014-10-09T13:58:12Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
Atkins, Timothy John. "Investigation of ultrasonic properties of MAGIC gels for pulse-echo gel dosimetry." Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/371793/.
Повний текст джерелаCourter, Erik Joseph-Leonard. "Use of ClearView Gel Dosimeter for Quality Assurance and Testing of Stereotactic Radiosurgery." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1466417256.
Повний текст джерелаJayasekera, Piyakeerthi Mangala. "Practical aspects of radiotherapy gel dosimetry." Thesis, Queensland University of Technology, 2000.
Знайти повний текст джерелаJardine, Paul. "Applications of gel based chemistry dosimetry." Thesis, Queensland University of Technology, 1994. https://eprints.qut.edu.au/37183/1/37183_Jardine_1994.pdf.
Повний текст джерелаSmith, Shaun T. "Development of gel dosimetry for radiotherapy." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/102759/1/Shaun_Smith_Thesis.pdf.
Повний текст джерелаZhang, Qing Jane. "Dynamic mathematical modeling of a polyacrylamide gel dosimeter." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63396.pdf.
Повний текст джерелаSilveira, Michely Cristina da. "Distribuição da dose absorvida no tratamento da micose fungóide através da dosimetria Fricke Xilenol Gel." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-04032011-155301/.
Повний текст джерелаRadioterapy uses ionizing radiation to destroy tumor cells. The absorbed dose control in a target volume is done through dosimetry, using radiation sensors, being the Fricke and film used in this study. Among several types of cancer indicated for treatment using ionizing radiation, there is also the Mycosis Fungoides (MF), lymphom that spreads on surface and depth in the skin, for which high-energy electrons are used for its treatment. In this work the Fricke Xylenol Gel (FXG) was used for MF treatment control, to obtain the absorbed dose distribution from electrons interaction with the tissues. For this scope cuvettes were manufactured of acrylic (slices), with the same contours of the skull and abdomen anthropomorphic simulator tomos. Once filled with the FXG, these cuvettes were used to infer the absorbed dose by the anthropomorphic simulator Rando Phantom. This simulator, completed with the cuvettes and radiochromic films, this last one also with the same contours similar to skull and abdomen were submitted to the Stanford technique, for 6 MeV electrons total body irradiation. CCD and radiographic density images were acquired and evaluated by horizontal and vertical profiles through theirs centers. These profiles were analyzed through a computer programs: one developed in Matlab for FXG images and the other by an already known program, ImageJ, for film images. From the results one can infer that the FXG dosimeter presents similarity with that of film, in the evaluation of the absorbed dose distribution on surface and also inside of the patient.
Neto, Euclydes Borguezan. "Gel Turnbull Blue aplicado à dosimetria de radiação ultravioleta e visível." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-22122016-135858/.
Повний текст джерелаThe radiochromic gel Turnbull Blue (TBG) is sensitive to gamma and x-rays. This compound has been utilized in ionizing radiation dosimetry, since it acts as biological tissue simulator when exposed to high-energy radiation. Subsequently to its radiation, TBG shows a color shift: the original yellow aspect becomes blue due to the production of the colorant Turnbull Blue. Such chromic shift yields a broad absorption band in the visible spectral range, with a peak located at 690 nm. The intensity of this band is proportional to the absorbed radiation dose. However, the behavior of TBG when exposed to less energetic radiation, e.g. ultraviolet and visible light, remains unclear. Considering the recommendations of international organizations regarding the risks of using such type of radiation, this research aimed to characterize the TBG response when irradiated by different ultraviolet and visible sources as well as to determine its sensitivity to the radiation in the UV-Visible spectral range. Furthermore, this investigation evaluated the viability of TBG as an optical dosimeter. During this study, the gel was exposed to different non-ionizing radiation sources, such as fluorescent lamps, LEDs and a sun simulator. The time between the gel exposition and the measurement of its response was studied, as well as the influence of different source irradiances and temperatures of irradiation. A spectrometer operating on the 350-900 nm spectral range has measured the gel color shift. The results showed different sensitivities according to the spectral range delivered by the source: UVC has produced the most intense change in color, followed by UVB, UVA and visible, respectively. The temperature of irradiation and the irradiance provided by the sources have shown considerable influence on the color shift. The results showed that it is possible to use the TBG gel as optical radiation dosimeter. The use of correction factors for temperature of irradiation and irradiance of the source are mandatory.
Bäck, Sven Å J. "Implementation of MRI gel dosimetry in radiation therapy." Malmö : Lund : Malmö University Hospital ; Lund University, 1998. http://catalog.hathitrust.org/api/volumes/oclc/68945079.html.
Повний текст джерелаSánchez, Mirko Salomón Alva. "Verificação 3D da distribuição da dose em radiocirurgia estereotáxica através de simulação Monte Carlo e dosimetria por ressonância magnética nuclear." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-15052013-193530/.
Повний текст джерелаStereotactic radiosurgery is a technique which delivers high radiation doses using small fields to conform the absorbed dose into the target volume. Due to the complexity of this technique it is necessary to verify the dose distribution in the treatment volume. Thus, in this study the three-dimensional (3D) dose distributions of selected clinical cases of cranial tumors were obtained using a head phantom. The the dose distributions of target volumes and adjacent regions were evaluated with PENELOPE Monte Carlo simulation code, MAGIC-f dosimeter and iPlan® treatment planning system. Radiochromic films were also used to determine the dose distribution on selected plans of the treatment. The obtained results for the proposed dosimetric tools were analyzed by the gamma index distributions, comparing the maps of the central dose distributions obtained with the four dosimetric tools. Using the dose criteria of 3% in 3 mm, the gamma index test showed equivalence in the region of dose prescription (95% isodose) and a different result was observed for lower isodoses, with maximum accordance of 76.5%. The volumetric dose distributions obtained with PENELOPE, MAGIC-f and iPlan were also compared using the dose-volume histograms for each studied case, showing that 95% of the absorbed dose yield within the target volume. The tumor control probability, TCP, was evaluated for the studied radiosurgery cases, from the dose distributions-volumetric, resulting in a maximum probability of tumor control of 72% for all cases, for the used mathematical model of TCP. From the results it can be inferred that the MAGIC-f gel dosimeter and the PENELOPE Monte Carlo simulation code can be used to determine 3D dose distributions for stereotactic radiosurgery. These dosimetric tools can assist the commissioning of treatment units and 3D dose verifications of patients treatments, allowing assessments in and around the target volume and may become routine in radiotherapy services.
Farvis, Francis. "Optical properties of polymer dosimeter gels." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/13151.
Повний текст джерелаOliveira, Lucas Nonato de. "Parâmetros dosimétricos e coeficiente de difusão para elétrons em campos pequenos, através do dosímetro Fricke Xilenol Gel." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-06062008-173808/.
Повний текст джерелаDosimetric parameters such as Percentage Depth Dose, Field Profile and Output Factor are necessary in radiotherapy routine, once they can help to improve the quality of the treatment and consequently of the absorbed dose delivered to the tumor. In this work the dosimetric parameters for electron beams of 8 and 10 MeV were measured with the chemical dosimeter Fricke Xylenol Gel for small field sizes (square and circular) and were compared with those obtained with an ionization chamber. The chemical dosimeter signal, given by the complex Fe+3 - Xylenol concentration, has a temporal dependency, to which its diffusion coefficient was determined together with the activation energy, necessary for the Fe+3 migrations in the gel. These two parameters were measured, for the first time, for the Fricke Xylenol Gel and for that a novel methodology was also created. The measured parameters, dosimetric ones together with the diffusion coefficient and activation energy corroborate, to present the chemical dosimeter, as an adequate one to be used in radiotherapy with electron beams for small field sizes.
Hepworth, Stephen J. "Investigations into polymer gel dosimetry using magnetic resonance imaging." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/978/.
Повний текст джерелаAlrushoud, Abdullah A. "Polymer gel dosimetry in radiation therapy using computed tomography." Thesis, University of Surrey, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616921.
Повний текст джерелаKhoei, Shadi. "Quantitative ultrasound computed tomography imaging of PAGAT radiation dosimetry gel." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/63958/1/Shadi_Khoei_Thesis.pdf.
Повний текст джерелаPavoni, Juliana Fernandes. "Dosimetria tridimensional por imagens de ressonância magnética com gel MAGIC modificado." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-27042010-171038/.
Повний текст джерелаAdvances in the treatment techniques with ionizing radiation are resulting in complex dose distributions that need to be verified before the application of the treatment in the patient. Several dosimeters have been suggested for this application, but polymeric gel dosimeters are presenting the best results so far, since they allow three dimensional dose visualization, are tissue equivalent, don\'t have dependence with angular distribution of the incident radiation and have a high spatial resolution. In this work a polymeric gel dosimeter with national components, to reduce de costs and facilitate its introduction in the clinical practice was developed. Formaldehyde was added to the gel formulation to increase its melting temperature and facilitate its use in typical room temperatures found in our country. Dose response analysis was done using nuclear magnetic resonance relaxometry. All the dosimetric characterization was done. We found a linear dose-response curve for doses until 15Gy and significant energy dependence for low energy beams (kVp), but for high energy beams (MV) this dependence is smaller. The response variation when varying the dose rate of irradiation was smaller than 5% in the dose rate range of clinical use in teletherapy (100-600cGy/min). The addition of formaldehyde did not eliminate the dosimeter dependence with variation of the scanning temperature; the integrity of dose distribution was unaltered at least for a tree month period of time in a half beam irradiation phantom. Tri-dimensional dose distributions were measured in two radiotherapy systems using intensity modulated beams, the first one in a linear accelerator and the second in a tomotherapy machine. A high similarity was found between the overlapping of isodoses and dose profiles of the dose distribution measured with the gel and expected by the treatment planning. The real tri- dimensional analysis was done with dose-volume histograms (DVH) and the DVHs measured for the planning volume and expected by the treatment planning were in good agreement. Our results show that the modification done in the gel formulation resulted in a dosimeter easy to handle and feasible for tri-dimensional measurements.
Brodeur, Marylène. "Verification of IMRT beam delivery with a ferrous sulfate gel dosimeter and MRI." Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=78331.
Повний текст джерелаThe gel dosimeter system is tested through a set of simple experiments which characterize and confirm the system as a valid QA tool for conformal and intensity modulated radiation therapy.
For this work, dynamic photon beams are created on a commercially available inverse treatment planning system and the treatment is delivered to a gel filled acrylic mold. Software has been developed to quantify dose from the QA MR images, and to register this information to the planning computed tomography (CT) scan. The software displays the measured dose on the planning CT, and calculates dose-volume histograms for the registered measured data and contoured patient structures. This work reveals good agreement between planned and measured dose distributions, with less than 5% difference in the mean doses of the contoured patient structures.
Farajollahi, Ali Reza. "An investigation into the applications of polymer gel dosimetry in radiotherapy." Thesis, Online version, 1998. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.284699.
Повний текст джерелаValente, M. A. "Fricke gel dosimetry for 3D imaging of absorbed dose in radiotherapy." Doctoral thesis, Università degli Studi di Milano, 2007. http://hdl.handle.net/2434/41638.
Повний текст джерелаResende, Thiago Dias. "Um estudo para otimização da formulação do dosímetro gel MAGIC-f e avaliação da sua reutilização." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-07072017-123749/.
Повний текст джерелаRadiotherapy is a procedure that uses high energy ionizing radiation directed to the tumor to destroy its cells. The objective is to obtain tumoral cells more damaged avoiding the healthy cells around it and increase this result. Due to the high complexity of the energy beams used on these treatments, a three-dimensional dosimeter is demanded to assure that the dose is focused as planned, being the polymeric gel dosimetry using Nuclear Magnetic Resonance Images (NMRI) for dose scanning an option to this measurement. This work uses MAGIC-f gel as reference and its objective is to optimize the dosimeter formulation, by initiallyreplacing the antioxidants agents (Copper Sulfate and Ascorbic Acid) by a more power rating antioxidant, Tetrakis (hydroxymethyl) phosphonium chloride (THPC), and then, variatingthe others dosimeter´s components concentration in order to obtain the smallest concentration of each one that result in an adequate dosimeter´ssensitivity for radiotherapy application. Studies were made to check the thermal stability of the gel containing THPC and studies were carried out about the ideals concentrations of THPC (2mM, 5mM, 8mM, 10mM or 20mM); Methacrylic Acid (2%, 2.5%, 3%, 3.5% or 4%); Gelatin (4%, 6%, 8% or 10%). After the modifications, the optimized formulation containing 88.96% of mili-Q water; 3% of methacrylic acid; 8% of gelatine; 0.04% of THPC (5mM) showed a sensitivity of approximately 1.03 Gy-1s-1 and a melting point approximately of 50°C, using the smallest possible chemical compounds concentrations and the NMRI scanning sequence implemented for this dosimetry. The optimized dosimeter obtained presents a 40% cost reduction, comparing with the dosimeter MAGIC-f, and a dose resolution of 0.18 Gy. The dosimeter responds linearlywith doses from 0 to 10 Gy. A maximal sensitivity variation of 8.5% was found when varing the dose rate from 300 to 500 cGy/min. Its dose integrity was checked by a half beam blocked irradiation. And its largestsensitivity variation at a repeatability test was 15%. The second objective of this work was the development of a methodology for reusing the dosimeter.The dosimeter previously irradiated with 2Gy was reused after being melted in a digitaltemperature control oven at 50°C, followed by the re-addition of THPC and a new gelation. The reused MAGAT gel dosimeter with 1mM of THPC presented 30% sensitivity reductioin when compared to the the same dosimeter before the reusing process, while the MAGAT gel with 2mMof THPC presented a reduction of only 15%
Baldock, Clive. "Aspects of dosimetry using radiation sensitive gels." Thesis, King's College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249297.
Повний текст джерелаAsena, Andre. "Dosimetry in the vicinity of high-density materials in radiotherapy." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/103983/1/Andre_Asena_Thesis.pdf.
Повний текст джерелаAmin, Md Nurul. "Polymer gel dosimetry applied to β particles, electrons and 300 kV X-rays". Thesis, University of Leicester, 2003. http://hdl.handle.net/2381/29451.
Повний текст джерелаSakuraba, Roberto Kenji. "Desenvolvimento de um sistema de verificação dosimétrica tridimensional utilizando Solução Fricke gel na aplicação para a verificação da Radioterapia em Arco Modulado Volumétrico (VMAT) nos tratamentos com movimentação do alvo pela respiração." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-03032016-091027/.
Повний текст джерелаVolumetric Modulated Arc Therapy (VMAT) is one of the methods most commonly used in teletherapy to treat cancer. The various technological advances and the evolution of treatment techniques made the VMAT as one of the state of the art methods for the treatment of some cancers. Part of this improvement is credited to improvements in accuracy and prescription dose absorbed recommended to the patient over the years. This advance allows currently is possible to perform dosimetric calculations by means of the computerized planning system, considering the heterogeneity of patients, such as tissues and organs with different water compositions medium (reference radiation), and individual patient contour the movement of tumors breathing. Such advances require quality control of these tools, in order to ensure that the entire treatment process is satisfactory and accurate. Up to now, the community lacks an experimental system capable of evaluating, considering the uncertainty levels if the computerized planning systems are able to consider the movement of targets in the treatments with VMAT. In this paper, will be presented the results obtained with the phantom Fricke Xylenol Gel, capable of measuring the differences introduced by movement using the Magnetic Resonance Image - MRI and compared qualitatively and quantitatively. The main stages of the phantom development, their experimental results, conclusions and comparisons with other systems are discussed.
Gear, Jonathan. "Polymer gels for dosimetry in targeted radionuclide therapy." Thesis, Institute of Cancer Research (University Of London), 2009. http://publications.icr.ac.uk/10124/.
Повний текст джерелаHeathcote, Alan D. "The dual development of an optical tomographic scanner and three dimensional gel dosimeter for complex radiotherapy verification." Thesis, University of Hull, 2008. http://hydra.hull.ac.uk/resources/hull:764.
Повний текст джерелаMANGUEIRA, THYAGO F. "Avaliacao dosimetrica da solucao fricke gel usando a tecnica de espectrofotometria para aplicacao na dosimetria de eletrons e neutrons." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9447.
Повний текст джерелаMade available in DSpace on 2014-10-09T14:00:05Z (GMT). No. of bitstreams: 0
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Crescenti, Remo Andrea. "Backscatter ultrasound readout of radiation-sensitive gels for radiation dosimetry." Thesis, Institute of Cancer Research (University Of London), 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511163.
Повний текст джерелаVenning, Anthony James. "Investigation of radiation sensitive normoxic polymer gels for radiotherapy dosimetry." Thesis, Queensland University of Technology, 2006. https://eprints.qut.edu.au/16257/1/Anthony_Venning_Thesis.pdf.
Повний текст джерелаVenning, Anthony James. "Investigation of radiation sensitive normoxic polymer gels for radiotherapy dosimetry." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16257/.
Повний текст джерелаSandwall, Peter A. II. "Spatial Dosimetry with Violet Diode Laser-Induced Fluorescence of Water-Equivalent Radio-Fluorogenic Gels." Thesis, University of Cincinnati, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3625827.
Повний текст джерелаThe following work describes investigations of spatial dosimetry using laser-induced fluorescence of a radio-fluorogenic detector embedded within water-equivalent media. The chemical composition of a gelatin-based coumarin-3-carboxylic acid detector was investigated and dose response characterized. Violet diode (405nm) excitation sources were explored and laser-induced fluorescence (LIF) employed to obtain the pattern of fluorescent emission yielding images of the integrated spatial dose distribution. The design of a three-dimensional reader is proposed to provide a foundation for future work.
Radio-fluorogenic processes create fluorescent products in response to ionizing radiation. Water radiolysis produced by ionizing radiation yields hydroxyl free radicals that readily hydroxylate coumarin-3-carboxylic acid to 7-hydroxy-coumarin-3-carboxylic acid, a derivative of umbelliferone. Umbelliferone is a known fluorophore, exhibiting peak excitation in the UV to near UV range of 365-405nm with a visible 445nm blue emission. Coumarin-3-carboxlyic acid has been studied in an aqueous gelatin matrix.
The radio-fluorogenic coumarin-gelatin detector has been shown to respond to an absorbed dose of ionizing radiation in a measureable manner. The detector was studied with respect to concentration of gelatin and coumarin in the presence of pH buffers. Dose response of the detector was investigated with regard to ionizing radiation type, energy, and rate of irradiation. Results demonstrate a functional detector.
Patterns of energy deposition were formed in response to ionizing radiation produced by a sealed-source of radioactive Ir-192 embedded in the gelatin matrix of the detector. Spatial distributions of absorbed dose were recorded and analyzed as a function of fluorescent emission. The distribution of energy deposition was imaged with LIF excitation by a divergent beam of 405nm light and determined by analysis of digital image pixel intensity values displaying the 445nm fluorescent emission. Results demonstrate spatial dosimetry proof of principle.
A basic dedicated reader system was fabricated employing LIF. Images of fluorescent emission excitation profiles were obtained in multiple aqueous samples and processed to obtain a dose response. Design of an optical reader system for the radio-fluorogenic detector is explained and a three-dimensional dosimetry system proposed. Three-dimensional imaging principles with LIF have been illuminated.
Meesat, Ridthee. "Evaluation of the radiosensitizing or radioprotective/antioxidant potential of some selected compounds by polyacrylamide gel dosimetry and Fricke dosimeter, and utilization of the femtosecond infrared laser pulse filamentation as a novel, powerful beam for cancer radiotherapy." Thèse, Université de Sherbrooke, 2012. http://hdl.handle.net/11143/6246.
Повний текст джерелаPastorello, Bruno Fraccini. "Montagem e caracterização de um fantoma para utilização em radioterapia utilizando imagens convencionais por ressonância magnética e contraste por transferência de magnetização." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-11092007-160124/.
Повний текст джерелаThe 3D monomeric gel dosimetry is an important tool in radiation therapy cases which needs high spatial dose resolution. In this work we developed a methacrilic acid monomeric gel called MAGIC® to evaluate spatial dose distributions in simulations of radiation therapy treatments. We used two Magnetic Resonance Imaging (MRI) techniques, the relaxometry (RT) and the magnetization transfer (MT). The work was developed in three stages. First of all, the phantoms were created to be irradiated using and x radiations, the MRI were acquired and analyzed. We also developed a software, programmed in Matlab®, to analyze the images and to draw isodoses curves of irradiated phantoms. Following it, we improved the way the gel was prepared and its composition, as well the image acquisition and processing. In this part we added formaldehyde to the gel, improving its sensibility in 15%. Finally, we simulated 5 different radiation therapy treatments and compared the isodoses measured with the isodoses of the radiation therapy treatment planning software (TPS®). The results of the RT technique corresponded to our expectations. Using the RT we characterized the gel with dosimetric tests and evaluated five different radiation therapy treatments. The gel showed a linear relation with the dose until 20 Gy, but the results of the tests were not reproducibles, because of that we made a calibration curve for each test. The effective atomic number of the gel is close to the water, so it was not necessary any correction. In most of the simulated cases, the isodoses measured with the gel reproduced the virtual simulations. Unfortunately, until now, we didn\' t have the same success using the MT technique. The MT images were not reliable and because of that the simulations were only made with the RT technique.
Zahmatkesh, Mohammed. "Dosimetry of ionising radiation with ferrous and xylenol orange infused gels." Thesis, Queensland University of Technology, 1998.
Знайти повний текст джерелаMather, Melissa Louise. "Ultrasound evaluation of radiation sensitive polymer gels." Thesis, Queensland University of Technology, 2003.
Знайти повний текст джерелаCamargo, Shiva do Valle. "Confecção e caracterização de dosímetros luminescentes de cerâmicas de BaTiO3 nanoestruturadas." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-11072014-093623/.
Повний текст джерелаAccording to the literature, the study of Barium Titanate (BTO) for dosimetry is unpublished yet, this material was chosen because it exhibits luminescent properties, demonstrated in emission spectra experiments. To make the BTO samples the chemical sol-gel technique was used. Samples of BTO Pure, doped and co-doped with different rare earths were made. All produced samples were calcinated with temperatures at 800, 1000 and 1200°C. The doping was performed with the following rare earths: Nd, Tb, Eu, Yb, Er, Pr, and some samples were co-doped with Tb / Eu and Yb / Er; in total were made thirty-one samples. In the study of weight reduction, a reduction, by half of the mass of raw material, was observed during the calcination process. In the TL analysis, at least one of the types (temperature) of calcinations provides TL peaks formation, except for the samples co-doped with Tb / Eu. The BTO: Eu and Tb provided the best TL response. The BTO: Tb and calcined at 1200°C showed TL peak at 90 to 200°C and the one doped with Eu (1mol%) and calcined at 1000°C supplied peaks at 110°C and 370°C. The minimum detectable dose to the TL peak at 110°C was 119 mGy and for TL peak at 370°C was 143 mGy. SEM analyzes showed that the micrographs of BTO samples doped with both Tb and Eu supplied porous surfaces, unlike the pure sample, that showed smoother surface. XRD analyzes indicated a tetragonal phase to pure sample and the one doped with Eu (1 mol%), both calcined at 1000°C.
Paudel, Nava R. "Nanoparticle-aided Radiation Therapy: Micro-dosimetry and Evaluation of the Mediators Producing Biological Damage." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1403142628.
Повний текст джерелаZaias, Herofen. "Desenvolvimento de um novo gel e otimização de leitor para dosimetria química." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-30092010-110923/.
Повний текст джерелаResearchs with radiation dosimeters look for materials that presents similar response to radiation as biological systems. This work presents preliminar characterization and radiotherapy application from a new chemical dosimeter (FXGA), derived from the FXG with a difference due to the gelatin used (pork skin \"300 Bloom\" for FXG and national gelatin for FXGA). The FXGA absorbed dose reading are based on the optic absorption, and for this reason a reader (RADIARE III) was developed, which is portable and economically accessible when compared with an spectrophotometer. From the measurements done, it can be inferred that FXGA dosimeter possess linear response with the absorbed dose from 0.5 up to 35 Gy for 60Co photons and from up 1 up to 7 Gy for 5, 8 and 10 MeV. The energy dependence for photons and electrons were obtained and their response are coherent those expected. FXGA radiotherapy applications had been done as field factor, profile and percentage depth dose for 60Co photons. From the characterization results for photons and electrons, as well from physical parameters for the 60Co , one can figure out that the dosimetric system \"FXGA gel + RADIARE III reader\" can be an attractive tool for the quality control in a radiotherapy service.
Ventieri, Alexandre. "Síntese e caracterização de aluminatos de cálcio e lítio dopados com terras-raras para uso como detectores de radiações ionizantes." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-19122016-142840/.
Повний текст джерелаIn this work dosimetric proprieties of calcium and lithium aluminates synthetized by solgel technique and codoped/doped with rare earth europium and terbium were studied. Morphological characterization showed Ca12Al14O33 (C12A7) as a predominant phase, with grains size distribution between 150 -270 μm and a porous system between 200-290 nm for the sample calcined at 1100 °C. This calcination revealed the greatest luminescence results. The dopant incorporation phases, observed by XRD patterns, matches to CaEuAl3O7 and CaTbAl3O7 compounds. Luminescence characterization showed intense OSL signal when the samples were codoped with the concentration of 0,8 mol% of Eu,Tb. However, due to low TL-UV intensity, OSL signal could not be correlated with TL-UV glow curve of this aluminate. TL-VIS detection showed peaks at, 92, 216 and 310 °C for pure calcium aluminate and at 92, 135 and 216 °C for the codoped one. The lowest minimum detectable dose (MDD) obtained was 16 mGy in OSL detection from codoped calcium aluminate and the lowest fading was 5% from aluminate for 216 °C TL peak in VIS region. By Tm-Tstop studies and CGCD deconvolution TL-VIS glow curve could be fitted using 6 peaks, with general order kinetic, and CW-OSL decay curve was fitted with 4 components of second order. LMOSL experiments resulted in high photo-ionization cross-sections, which explains the optical response of this sample. For lithium aluminate, morphological characterization showed grains size dispersion between 25- 70 μm, with predominant phase of γ-LiAlO2 for pure sample, as well Al2Tb4O9 and TbAlO3 for Tb to doped one. Furthermore, SEM images showed long and longitudinal structures (500 nm) emerging from grain surface after Tb doping process. Luminescence characterization showed intense OSL, TL-UV and TL-VIS signals for sample doped with 0,2 mol% and calcined at 900 °C, which comprehends a complex luminescence system, with overlapping of 6 peaks in TL-VIS for pure aluminate (65, 100, 140, 203, 304 and 370 °C), 7 peaks for TL-VIS of doped one (70, 100, 140, 184, 211, 295 and 340 °C). The MDD obtained was 5 mGy for OSL and 2,2 mGy for 211 °C for TL-VIS peak, both for 0,2 mol% of Tb. The lowest fading was 1,5% for pure lithium aluminate of the 140 °C TL-VIS peak . By Tm-Tstop studies and CGCD deconvolution, TL-VIS glow curves were fitted using 9 peaks and for TLUV region, 8 and 7 peaks for pure and doped samples, respectively. Strictly, lithium aluminate revealed several energetic transfers evolving two possible depth trap explain by a simplified model of luminescence bands. The energetic transfer increments the final luminescence of the sample up to 2 times the initial OSL signal. Besides, even after 300 °C of thermal treatment, OSL signal keep its intense luminescence. However, the samples are highly sensitize by optical stimulation. In LM-OSL deconvolution, 4 components with elevated photo-ionization cross-sections were determined and fitted the experimental curve, which explains the highly optical sensitization.