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1
Sun, Jidi. "Implementation of 2-Step Intensity Modulated Arc Therapy." Thesis, University of Canterbury. Department of Physics and Astronomy, 2010. http://hdl.handle.net/10092/3844.
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Intensity modulated arc therapy is a novel treatment technique that has shown great potential to be superior to conventional intensity modulated radiotherapy, both in terms of treatment plan quality as well as treatment delivery. Based on previous literature, a simplified technique called two-step intensity modulated arc therapy (2-step IMAT) was implemented into a treatment planning system. In order to automatically generate treatment plans for this technique, a beam portal shaping method was developed to generate beam segments. A sensitivity analysis was carried out on a geometric phantom to determine optimal parameters for the 2-step IMAT implementation for that particular phantom. The segment weights were optimized using the dose-based and dose-volume-based objective functions. The optimal solution search was based on the gradient-descend algorithm. The dose-based objective function was implemented using a so-called lambda-value-dose-based objective function developed in this work in order to increase both speed and flexibility of the optimization. The successful implementation demonstrated the feasibility of automatic 2-step IMAT treatment planning.
A comparison of conventional arc therapy and 2-step IMAT showed improvements in the target dose uniformity by about 50% for both geometric phantom and clinical paraspinal tumor case, whilst also improving the organ sparing. The comparisons between the lambda-value-dose-based and dose-volume-based optimizations showed a speed advantage of the former by a factor of over five in the phantom study.
The current beam portal shaping approach can be improved by optimizing the segment width and including multiple organs-at-risk in the segment generation algorithm. Future work will also include the implementation of a stochastic optimization to minimize the chance of getting trapped in local minima during the segment weight optimization. In summary, the work of this research showed that the automatic 2-step IMAT planning is a viable technique that can result in highly conformal plans while keeping the treatment planning and delivery simple and straightforward.
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Xian, Zheng. "Dose verification of a stereotactic IMRT treatment planning system." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/23810.
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In this project, ion chamber measurement and film dosimetry were used to verify dose distributions for a new stereotactic IMRT (Intensity Modulated Radiation Therapy) treatment planning system. This technique combines the principles of stereotactic radiosurgery and IMRT to significantly increase the positioning accuracy compared with conventional IMRT . Ion chamber measurements reveal that the discrepancy between the measured and the calculated dose at the isocenter can be up to 2%. Angular dependence of ion chamber sensitivity and the tissue equivalence of the phantom material were determined to be the main sources of this discrepancy. Radiochromic film was used as the film dosimeter in the project. A set of performance tests of Gafchromic EBT film indicated that the uncertainty in Gafchromic EBT film dosimety was expected to be 2.5%. However, the discrepancies we found in measurements of clinical cases using the film were much larger than this. And further investigation into this discrepancy was beyond the scope of this thesis.
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Mackin, Neil. "Development of an expert system for planning orthodontic treatment." Thesis, University of Bristol, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238890.
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Vader, Ranjeet D. "Development of computer aided heat treatment planning system (CAHTPS)." Link to electronic thesis, 2002. http://www.wpi.edu/Pubs/ETD/Available/etd-0830102-113605.
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Gardner, Joseph Kingsley. "Integration of VMC++ into a Commercial Treatment Planning System." VCU Scholars Compass, 2005. http://scholarscompass.vcu.edu/etd/990.
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Recently, there has been interest to integrate VMC++ into the commercial treatment planning system at VCU as another Monte Carlo code option, since it has been shown to increase efficiency dramatically without introducing a significant amount of systematic error. Also, independent validation of VMC++ for photon beams is of interest since this has not been performed previously in literature. This study included several tests required to integrate VMC++. Output factor normalization was performed and found to agree with experiment to within 1% for all field sizes except 1x1 cm2. Geometric validation was successful. Dosimetric validation was performed with respect to DOSXYZnrc on a water phantom, resulting in agreement within statistical uncertainty except for slight differences at the surface of the phantom. Dosimetric comparison was made for a head-and-neck patient case, showing that 5% of the voxels did not agree within 2.8% of maximum dose. The ability of VMC++ to compute dose-to-water was compared to an in-house algorithm and found to agree within statistical uncertainty.
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Vaidya, Rohit Subhash. "Experimental testing of a computer aided heat treatment planning system." Link to electronic thesis, 2003. http://www.wpi.edu/Pubs/ETD/Available/etd-0827103-111212.
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Mathayomchan, Boonyanit. "MULTIOBJECTIVE APPROACH TO MORPHOLOGICAL BASED RADIATION TREATMENT PLANNING." Case Western Reserve University School of Graduate Studies / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=case1131365356.
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Orfali, Anas. "Verification of a 3D external photon beam treatment planning system." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=24374.
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Treatment planning is recognized as a fundamental step in clinical radiotherapy. The increased availability and complexity of three dimensional (3D) computerized treatment planning systems necessitates a full verification protocol to be completed prior to the implementation of the treatment planning system in routine use.<br>We have designed and performed a detailed experimental verification program aimed at evaluating each individual dosimetric aspect of our 3D computerized treatment planning system (Varian CADPLAN, version 2.62). The verification tests ranged in complexity from the most basic standard geometry to a simulation of a full treatment case. Results from each individual testing geometry are presented, and an overall evaluation is discussed. We have concluded that our 3D treatment planning system is acceptable for clinical use.
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Obata, Yasunori, and Hiroshi Oguchi. "Commissioning of modulator-based IMRT with XiO treatment planning system." AIP Publishing, 2009. http://hdl.handle.net/2237/20613.
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Nill, Simeon. "Development and application of a multi-modality inverse treatment planning system." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963121413.
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Comeau, Roch. "The design and implementation of a three dimensional computerized treatment planning system /." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69536.
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An efficient and productive radiation treatment planning (RTP) system must make use of both appropriate visualization techniques and good user interface design. The suitability of several visualization techniques have been examined in the context of 3-D radiation treatment planning. These techniques include wire frame, surface rendering, volume rendering and a subset of volume rendering: reformatting of data. A rudimentary computerized RTP system was written using the most appropriate visualization techniques examined earlier. These techniques were used to display the anatomical data acquired from computed tomography (CT) scanners, the beam position within the anatomy, and finally, the dose distributions resulting from the entered plan. The program was written in ANSI C and runs on a Silicon Graphics Personal Iris UNIX workstation. The system makes use of effective user interface tools and efficient code which results in an efficient and interactive system. The accuracy of the system is verified by comparing dose profiles obtained with film dosimetry and from the computer calculations.
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Williams, C. Lesley. "A computer-based decision support system for orthodontic diagnosis and treatment planning." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq21223.pdf.
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Jagannathan, Rupa. "A case-based reasoning system for radiotherapy treatment planning for brain cancer." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/29318/.
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In this thesis, a novel case-based reasoning (CBR) approach to radiotherapy treatment planning for brain cancer patients is presented. In radiotherapy, tumour cells are destroyed using ionizing radiation. For each patient, a treatment plan is generated that describes how the radiation should be applied in order to deliver a tumouricidal radiation dose while avoiding irradiation of healthy tissue and organs at risk in the vicinity of the tumour. The traditional, manual trial and error approach is a time-consuming process that depends on the experience and intuitive knowledge of medical physicists. CBR is an artificial intelligence methodology, which attempts to solve new problems based on the solutions of previously solved similar problems. In this research work, CBR is used to generate the parameters of a treatment plan by capturing the subjective and intuitive knowledge of expert medical physicists stored intrinsically in the treatment plans of similar patients treated in the past. This work focusses on the retrieval stage of the CBR system, in which given a new patient case, the most similar case in the archived case base is retrieved along with its treatment plan. A number of research issues that arise from using CBR for radiotherapy treatment planning for brain cancer are addressed. Different approaches to similarity calculation between cases are investigated and compared, in particular, the weighted nearest neighbour similarity measure and a novel non-linear, fuzzy similarity measure designed for our CBR system. A local case attribute weighting scheme has been developed that uses rules to assign attribute weights based on the values of the attributes in the new case and is compared to global attribute weighting, where the attribute weights remain constant for all target cases. A multi-phase case retrieval approach is introduced in which each phase considers one part of the solution. In addition, a framework developed for the imputation of missing values in the case base is described. The research was carried out in collaboration with medical physicists at the Nottingham University Hospitals NHS Trust, City Hospital Campus, UK. The performance of the developed methodologies was tested using brain cancer patient cases obtained from the City Hospital. The results obtained show that the success rate of the retrieval mechanism provides a good starting point for adaptation, the next phase in development for the CBR system. The developed automated CBR system will assist medical physicists in quickly generating treatment plans and can also serve as a teaching and training aid for junior, inexperienced medical physicists. In addition, the developed methods are generic in nature and can be adapted to be used in other CBR or intelligent decision support systems for other complex, real world, problem domains that highly depend on subjective and intuitive knowledge.
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Miller, William Harley. "AN INTRODUCTION TO A HYPERTHERMIA PATIENT PLANNING AND PATIENT TREATMENT EVALUATION SYSTEM (NUMERICAL, CANCER)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275373.
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Staley, Noah D. "An Investigation into the Accuracy of the Photon Beam Energy Spectrum Modeled by the Pinnacle Treatment Planning System and Its Effects on Treatment Planning." University of Toledo Health Science Campus / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=mco1481308003486075.
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DeBlois, François. "Implementation of 3D external photon beam dosimetry for the McGill Treatment Planning System." Thesis, McGill University, 1996. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23881.
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A clinically-useful treatment planning system for external photon beam radiotherapy must yield fast and accurate calculations of the dose distribution in the patient. The interface of the system should be "user friendly" and designed to minimize user work and errors. Visualization of the patient volume and dose calculation results should provide necessary formation without being confusing. A software module meeting these criteria has been implemented within the McGill Treatment Planning System (MPS). The MPS program is written in C code and compiled with CodeWarrior C/C++$ rm sp{TM}$ from MetroWerks Inc. The MPS program runs on the Apple Macintosh platform (either 68K or PowerPC series). This new software module permits dose calculation (modified Milan-Bentley method) and viewing of the patient volume in three dimensions. Patient anatomical data is acquired from computed tomography (CT) or magnetic resonance (MRI) images. The accuracy of the dose calculation has been verified through comparison of the calculated results with water tank and film measurements.
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Asiev, Krum. "Validation of a Monte Carlo based treatment planning system (TPS) for electron beams." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101700.
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A commercial electron dose calculation software (Eclipse TM) implementation based on the Macro Monte Carlo algorithm has been introduced. Eclipse™ initial configurations were performed for all available electron beam energies 6, 9, 12, 16, and 20 MeV. We evaluated the electron Monte Carlo (eMC) module of the Eclipse™ using a verification data set comprised of depth dose curves, profiles, Relative Output Factors (ROF), and 2-0 dose distributions in the transverse plane in a homogeneous phantom. The verification data set was comprised of measurements performed for combinations of 6, 9, 12, 16, and 20 MeV beam energies with five standard field sizes and thirteen irregularly shaped fields under three phantom setups. The phantom setups were normal beam incidence at source-to-surface distance (SSO) = 100cm, normal incidence with extended SSO=11 Ocm, and oblique incidence with extended SSO=11 Ocm. Calculations were performed in a digital phantom with the maximum number of particles accepted by Eclipse ™ with a grid spacing that was no larger than approximately one-tenth the distal falloff distance of the electron depth dose curve from 80% to 20% of the maximum dose. Overall, the agreement between the calculated dose distributions and measured on es was good for fields larger than 2 cm to better than 3% dose difference and 3 mm distance-to-agreement.
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Wiersma, Jan. "Hyperthermia treatment planning for the AMC-4 system using the WF-CGFFT method /." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2005. http://dare.uva.nl/document/49937.
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Lyons, Kristopher Aaron. "Evaluating the Dosimetric Impact of Treatment Couch Modeling in the RayStation TPS." University of Toledo Health Science Campus / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=mco1588675720197405.
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Norrby, Elias. "Investigation and Implementation of a Log Management and Analysis Framework for the Treatment Planning System RayStation." Thesis, Uppsala universitet, Avdelningen för beräkningsvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-354921.
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The purpose of this thesis is to investigate and implement a framework for log management and analysis tailored to the treatment planning system (TPS) RayStation. A TPS is a highly advanced software package used in radiation oncology clinics, and the complexity of the software makes writing robust code challenging. Although the product is tested rigorously during development, bugs are present in released software. The purpose of the the framework is to allow the RayStation development team insight into errors encountered in clinics by centralizing log file data recorded at clinics around the world. A framework based on the Elastic stack, a suite of open-source products, is proposed, addressing a set of known issues described as the access problem, the processing problem, and the analysis problem. Firstly, log files are stored locally on each machine running RayStation, some of which may not be connected to the Internet. Gaining access to the data is further complicated by legal frameworks such as HIPAA and GDPR that put constraints on how clinic data can be handled. The framework allows for access to the files while respecting these constraints. Secondly, log files are written in several different formats. The framework is flexible enough to process files of multiple different formats and consistently extracts relevant information. Thirdly, the framework offers comprehensive tools for analyzing the collected data. Deployed in-house on a set of 38 machines used by the RayStation development team, the framework was demonstrated to offer solutions to each of the listed problems.
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Thébaut, Jonathan. "Measurement driven, electron beam modeling and commissioning for a Monte Carlo treatment planning system with improved accuracy." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=67026.
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With the development of modern linear accelerators, the dosimetry of complex electron beams technique became a challenge for physicists. Over the past few years, lots of efforts have been done on developing accurate and fast dose algorithms for electrons. Numerous Monte Carlo (MC) models of therapeutic electron beams are presented in the literature. However, beam models built solely with manufacturer specifications of the medical accelerator do not systematically provide acceptable agreements with measurements. Clinically accurate beam models are crucial to MC treatment planning as electron dose calculations found in commercial treatment planning system (TPS) are generally inaccurate for complex geometry or with heterogeneities. Therefore, there is a strong motivation to use highly accurate MC simulations as standard information for commissioning commercial TPS. The current research project consists in developing an improved accurate electron beam model based on detailed information of the linear accelerator and to incorporate it into an in-house TPS: The McGill Monte Carlo Treatment Planning (MMCTP).<br>Avec le développement d'accélérateurs linéaires, la dosimétrie de techniques complexes de faisceaux d'électrons devient un défi pour les physiciens. Ces dernières années, des efforts considérables ont été faits pour développer un algorithme de calcul de dose précis et rapide pour les faisceaux d'électrons. De nombreux modèles Monte Carlo (MC) pour des faisceaux thérapeutiques d'électrons sont connus dans la littérature. Néanmoins, des modèles de faisceaux construits seulement avec les spécifications des constructeurs d'accélérateurs linéaires ne fournissent pas systématiquement des résultats en concordance avec les mesures. Au niveau clinique, des modèles de faisceaux précis sont d'une importance capitales pour les calculs de dose par Monte Carlo, dans la mesure où les algorithmes de calcul de faisceaux d'électrons présents dans les systèmes de plannification de traitements (SPT) commerciaux sont générallement imprécis dans des cas comportant des geométries complexes ou des hétérogénéités. Par conséquent, il y a une grande motivation à utiliser des simulations de Monte Carlo précis, comme information standard pour la mise en service des SPT commerciaux. La recherche présentée dans ce manuscrit vise à développer un modèle amélioré et précis de faisceaux d'électrons basé sur des informations détaillées d'accélérateurs linéaires et à incorporer ce modèle dans un SPT: le « McGill Monte Carlo Treatment Planning (MMCTP) ».
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Zanna, Bonacorsi Alice. "Out-of-field organs doses in radiotherapy procedures: calculations by treatment planning system vs measurements by radiochromic films." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10715/.
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Il crescente interesse nell'ambito della radioterapia verso le dosi agli organi fuori dal campo di trattamento, ha spinto a dedicare questo lavoro di tesi al confronto tra dosi agli organi fuori campo calcolate mediante treatment planning system (TPS) e misurate tramite film radiocromici. I film radiocromici hanno un'alta risoluzione spaziale e sono particolarmente indicati per effettuare misure dosimetriche con fantocci antropomorfi. La regione testa-collo è particolarmente interessante dal punto di vista dosimetrico poiché in essa si raggiungono alte dosi di prescrizione e sono presenti numerosi organi. In particolare, si è deciso di fare le misure in corrispondenza dei cristallini e di un punto di riferimento all'interno del cervello.La tesi è stata svolta presso il Servizio di Fisica Sanitaria e presso le Unità Operative di Radioterapia del Policlinico S.Orsola-Malpighi.Le misure sono state effettuate mediante l'utilizzo dell'acceleratore lineare Siemens Oncor, di pellicole Gafchromic EBT3, di un fantoccio antropomorfo Alderson Rando e del TPS Pinnacle 9.10, prendendo in esame casi-studio rappresentativi dei trattamenti radioterapici nella regione testa-collo. Il confronto tra le dosi predette dal TPS e misurate con le pellicole radiocromiche ha mostrato che il TPS sottostima in media la dose misurata del 24% per i cristallini e del 26% per il punto di riferimento rappresentativo del tessuto cerebrale. Questi risultati evidenziano la criticità del TPS nella valutazione delle dosi agli organi fuori campo e sono in accordo con gli studi sperimentali presenti in letteratura.I risultati ottenuti rappresentano un importante elemento di attenzione per clinici e ricercatori e uno strumento per interpretare in maniera più corretta le informazioni fornite dal TPS. Questo è particolarmente utile per quei tessuti e organi, come il cristallino, che mostrano una elevata radiosensibilità e possono essere soggetti a danni deterministici anche con valori di dose di alcuni gray.
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Leheta, Dimitra. "Acquisition and Analysis of Megavoltage Linac Beam Transmission Data for Direct Verification of Photon Spectra Models in a Treatment Planning System." University of Toledo Health Science Campus / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=mco1416566156.
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Rice, Brandon. "Methods for producing off-axis ratio tables from mini-multileaf collimator shaped circular fields for input into a stereotactic radiosurgery treatment planning system." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0010840.
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Bellinzona, Valentina Elettra [Verfasser], and Katia [Akademischer Betreuer] Parodi. "A non Gaussian model for the lateral dose evaluation in hadrontherapy : development and Treatment Planning System implementation / Valentina Elettra Bellinzona ; Betreuer: Katia Parodi." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2017. http://d-nb.info/1127528068/34.
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Singh, Amarjit Kumar. "Development of Computer Aided Heat Treatment Planning System for Quenching & Tempering (CHT - q/t) and Industrial Application of CHT-bf & CHT-cf." Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-050306-224714/.
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Bartzsch, Stefan [Verfasser], and Uwe [Akademischer Betreuer] Oelfke. "Microbeam Radiation Therapy – physical and biological aspects of a new cancer therapy and development of a treatment planning system / Stefan Bartzsch ; Betreuer: Uwe Oelfke." Heidelberg : Universitätsbibliothek Heidelberg, 2014. http://d-nb.info/1180300246/34.
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Wan, Jui. "Exploring RayStation Treatment Planning System: Commissioning Varian TrueBeam Photon and Electron Energies, and Feasibility of Using FFF Photon Beam to Deliver Conventional Flat Beam." University of Toledo Health Science Campus / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=mco1501843246429305.
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Dowling, T. J. ""Sustainable development in water and sanitation" : a case study of the water and sanitation system at the Lynedoch Ecovillage Development." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/1041.
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Thesis (M.Phil. (School of Public Management and Planning))--University of Stellenbosch, 2007.<br>ENGLISH ABSTRACT: Water and sanitation is one of the key factors in the socio-economic development of a nation and people. Billions of people worldwide do not have access to clean water or basic sanitation leading to many health problems and developmental issues. This article discusses the challenges facing the world, South Africa and in particular the Western Cape and Cape Town in the provision of water and sanitation. For most people the desire is to have access to their own private portable water supply and their own private flush toilet connected via costly bulk water services to sewage treatment plants far away.
The question posed is whether this model is sustainable into the future, given the water demands in many parts of the world affected by droughts and more violent weather cycles as a result of climate change and global warming. These factors will affect water supplies in South Africa and in particular the Western Cape and Cape Town. To answer some of the questions raised the Lynedoch EcoVillage development is discussed in detail in terms of sustainable neighbourhood planning and implementation. Sustainable Development is discussed, also various options in terms of applying ecological sanitation. The on-site water and sanitation system of the Lynedoch EcoVillage is discussed as a case study. The results of influent and effluent tests conducted by the CSIR are analysed to see whether the system is conforming to the Department of Water Affairs and Forestry standards for the use of effluent water in irrigation and re-use of water in toilets.
Localised models of water and sanitation provision might thus be a way forward to satisfy the increasing demand for such services made on national and local authorities as urban areas increase in size and population.
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Neal, II Robert Evans. "Irreversible Electroporation Therapy for the Treatment of Spontaneous Tumors in Cancer Patients." Diss., Virginia Tech, 2011. http://hdl.handle.net/10919/51741.
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Irreversible electroporation is a minimally invasive technique for the non-thermal destruction of cells in a targeted volume of tissue, using brief electric pulses, (~100 µs long) delivered through electrodes placed into or around the targeted region. These electric pulses destabilize the integrity of the cell membrane, resulting in the creation of nanoscale defects that increase a cell’s permeability to exchange with its environment. When the energy of the pulses is high enough, the cell cannot recover from these effects and dies in a non-thermal manner that does not damage neighboring structures, including the extracellular matrix. IRE has been shown to spare the major vasculature, myelin sheaths, and other supporting tissues, permitting its use in proximity to these vital structures. This technique has been proposed to be harnessed as an advantageous non-thermal focal ablation technique for diseased tissues, including tumors.
IRE electric pulses may be delivered through small (ø ≈ 1 mm) needle electrodes, making treatments minimally invasive and easy to apply. There is sub-millimeter demarcation between treated and unaffected cells, which may be correlated with the electric field to which the tissue is exposed, enabling numerical predictions to facilitate treatment planning. Immediate changes in the cellular and tissue structure allow real-time monitoring of affected volumes with imaging techniques such as computed tomography, magnetic resonance imaging, electrical impedance tomography, or ultrasound. The ability to kill tumor cells has been shown to be independent of a functioning immune system, though an immune response seems to be promoted by the ablation. Treatments are unaltered by blood flow and the electric pulses may be administered quickly (~ 5 min).
Recently, safety and case studies using IRE for tumor therapy in animal and human patients have shown promising results. Apart from these new studies, previous work with IRE has involved studies in healthy tissues and small cutaneous experimental tumors. As a result, there remain significant differences that must be considered when translating this ablation technique towards a successful and reliable therapeutic option for patients. The dissertation work presented here is designed to develop irreversible electroporation into a robust, clinically viable treatment modality for targeted regions of diseased tissue, with an emphasis on tumors. This includes examining and creating proving the efficacy for IRE therapy when presented with the many complexities that present themselves in real-world clinical patient therapies, including heterogeneous environments, large and irregular tumor geometries, and dynamic tissue properties resulting from treatment. The impact of these factors were theoretically tested using preliminary in vitro work and numerical modeling to determine the feasibility of IRE therapy in heterogeneous systems. The feasibility of use was validated in vivo with the successful treatment of human mammary carcinomas orthotopically implanted in the mammary fat pad of mice using a simple, single needle electrode design easily translatable to clinical environments.
Following preliminary theoretical and experimental work, this dissertation considers the most effective and accurate treatment planning strategies for developing optimal therapeutic outcomes. It also experimentally characterizes the dynamic changes in tissue properties that result from the effects of IRE therapy using ex vivo porcine renal cortical tissue and incorporates these into a revised treatment planning model. The ability to use the developments from this earlier work is empirically tested in the treatment of a large sarcoma in a canine patient that was surgically unresectable due to its proximity to critical arteries and the sciatic nerve. The tumor was a large and irregular shape, located in a heterogeneous environment. Treatment planning was performed and the therapy carried out, ultimately resulting in the patient being in complete remission for 14 months at the time of composing this work.
The work presented in this dissertation finishes by examining potential supplements to enhance IRE therapy, including the presence of an inherent tumor-specific patient immune response and the addition of adjuvant therapeutic modalities.<br>Ph. D.
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De, Pietri Marco. "Development of a Human Unstructured Mesh Model Based on CT Scans for Dose Calculation in Medical Radiotherapy." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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Questo lavoro di tesi analizza l’opportunità di applicare dei metodi Monte Carlo nei campi della Radioterapia Superficiale e Ortovoltaica. Inizialmente i protocolli di cura attualmente esistenti sono stati studiati. Una revisione della letteratura è stata condotta sulle tipologie ed evoluzione dei fantocci umani computazionali. I passaggi pratici per la realizzazione di due tipi di fantocci basati su paziente, partendo da immagini TAC, sono stati descritti. Questi due tipi, modelli voxel e modelli a mesh non strutturate, sono stati studiati e comparati attraverso simulazioni. Dalla collaborazione con il reparto di Fisica Medica dell’Arcispedale S. Maria Nuova di Reggio Emilia, un modello di un tubo a Raggi X è stato modellato e validato con misure sperimentali. Questa sorgente è stata utilizzata su fantocci di teste attraverso simulazioni con MCNP6. In particolare è stata valutata la distribuzione spaziale della dose, dentro al modello, a tensioni crescenti all’interno del tubo. Il confronto dei risultati delle simulazioni ha permesso di valutare le interazioni dei fotoni all’interno del modello e le dosi al Planning Target Volume (PTV) e Organ At Risk (OAR) a tensioni della sorgente crescenti. Queste applicazioni hanno dimostrato che un prototipo di Sistema di Piano di Trattamento (TPS) è facilmente implementabile e può fornire preziose informazioni aggiuntive su questi tipi di radioterapia. Sebbene i protocolli esistenti siano in uso da molti anni, con innegabili tassi di cura elevati, è opinione dell’autore che l’integrazione di un TPS basato su Monte Carlo possa fornire potenziali benefici a questi tipi di radioterapia. In particolare, potrebbe fornire informazioni aggiuntive sulla scelta dei parametri di trattamento, portando a migliori risultati nella terapia e qualità di vita del paziente oncologico.
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De, Marzi Ludovic. "Effets physiques et biologiques des faisceaux de protons balayés : mesures et modélisation pour des balayages séquentiels à haut débit." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS546/document.
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L'objectif principal de cette thèse est de développer et optimiser les algorithmes caractérisant les propriétés physiques et biologiques des mini-faisceaux de protons pour la réalisation des traitements avec modulation d'intensité. Un modèle basé sur la superposition et décomposition des mini-faisceaux en faisceaux élémentaires a été utilisé. Un nouveau modèle de description des mini-faisceaux primaires a été développé à partir de la sommation de trois fonctions gaussiennes. Les algorithmes ont été intégrés dans un logiciel de planification de traitement, puis validés expérimentalement et par comparaison avec des simulations Monte Carlo. Des approximations ont été réalisées et validées afin de réduire les temps de calcul en vue d'une utilisation clinique. Dans un deuxième temps, un travail en collaboration avec les équipes de radiobiologie de l'institut Curie a été réalisé afin d'introduire des résultats radiobiologiques dans l'optimisation biologique des plans de traitement. En effet, les faisceaux balayés sont délivrés avec des débits de dose très élevés (de 10 à 100 Gy/s) et de façon discontinue, et l'efficacité biologique des protons est encore relativement méconnue vue la diversité d'utilisation de ces faisceaux : les différents modèles disponibles et notamment leur dépendance avec le transfert d'énergie linéique ont été étudiés. De bons accords (écarts inférieurs à 3 % et 2 mm) ont été obtenus entre calculs et mesures de dose. Un protocole d'expérimentation pour caractériser les effets des hauts débits pulsés a été mis en place et les premiers résultats obtenus sur une lignée cellulaire suggèrent des variations d'efficacité biologique inférieures à 10 %, avec toutefois de larges incertitudes<br>The main objective of this thesis is to develop and optimize algorithms for intensity modulated proton therapy, taking into account the physical and biological pencil beam properties. A model based on the summation and fluence weighted division of the pencil beams has been used. A new parameterization of the lateral dose distribution has been developed using a combination of three Gaussian functions. The algorithms have been implemented into a treatment planning system, then experimentally validated and compared with Monte Carlo simulations. Some approximations have been made and validated in order to achieve reasonable calculation times for clinical purposes. In a second phase, a collaboration with Institut Curie radiobiological teams has been started in order to implement radiobiological parameters and results into the optimization loop of the treatment planning process. Indeed, scanned pencil beams are pulsed and delivered at high dose rates (from 10 to 100 Gy/s), and the relative biological efficiency of protons is still relatively unknown given the wide diversity of use of these beams: the different models available and their dependence with linear energy transfers have been studied. A good agreement between dose calculations and measurements (deviations lower than 3 % and 2 mm) has been obtained. An experimental protocol has been set in order to qualify pulsed high dose rate effects and preliminary results obtained on one cell line suggested variations of the biological efficiency up to 10 %, though with large uncertainties
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Vautrin, Mathias. "Planification de traitement en radiothérapie stéréotaxique par rayonnement synchrotron. Développement et validation d'un module de calcul de dose par simulations Monte Carlo." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00641325.
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La radiothérapie stéréotaxique par rayonnement synchrotron (SSRT) est une technique innovanteutilisant un faisceau synchrotron de rayons X monochromatiques entre 50 et 100 keV. Une augmentationde dose par prise de contraste est obtenue localement par effet photoélectrique sur unélément lourd injecté dans le volume cible (tumeur cérébrale). Des essais cliniques de SSRT sont encours de préparation à l'ESRF (établissement européen de rayonnement synchrotron). Un systèmede planification de traitement (TPS) est nécessaire pour le calcul de l'énergie déposée au patient(dose) pendant le traitement. Une version dédiée du TPS ISOgray a donc été développée. Ce travaildécrit l'adaptation du TPS réalisée, particulièrement au niveau du module de simulation virtuelleet de dosimétrie. Pour un calcul de dose, le TPS utilise une simulation Monte Carlo spécifique desphotons polarisés et de basse énergie. Les simulations sont réalisées depuis la source synchrotron,à travers toute la géométrie de la ligne de lumière modélisée et dans le patient. Pour ce calcul, desmatériaux spécifiques ont été notamment ajoutés pour la modélisation voxélisée du patient, afin deprendre en compte la présence d'iode dans certains tissus. Le processus de calcul Monte Carlo a étéoptimisé en vitesse et précision. De plus, un calcul des doses absolues et des temps d'irradiation,particulier à la SSRT, a été ajouté au TPS. Grâce à des mesures de rendements, profils de dose, etdoses absolues, réalisées à l'ESRF en cuve à eau et en fantôme solide avec ou sans couche d'os, lecalcul de dose du TPS a été validé pour la SSRT.
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Campanelli, Henrique Barcellos. "Avaliação do sistema computadorizado de planejamento radioterápico XiO 5.10 – aspectos funcionais e avanços tecnológicos para melhoria da resposta terapêutica dos tratamentos." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153158.
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Previous issue date: 2018-02-23<br>Outra<br>Este trabalho apresenta um estudo de planos radioterápicos realizados com o Sistema de Planejamento de Tratamento (TPS) XiO 5.10, utilizados em centros de radioterapia. Foram analisados os protocolos clínicos de radioterapia através de pesquisa bibliográfica em artigos científicos e textos produzidos pelas sociedades especializadas da área da radioncologia. Foram realizadas visitas técnicas junto a serviços de radioterapia para melhor entendimento das diferenças entre os distintos sistemas de planejamentos radioterápicos aplicados. A pesquisa verificou a resposta de três diferentes algoritmos computacionais de cálculo de dose de radiação: Superposition, Convolution e Fast Superposition, disponíveis no TPS XiO® da Elekta Medical Systems. Para isto foram analisados os parâmetros de distribuição de dose para 22 planejamentos radioterápicos realizados em uma clínica de radioterapia privada, sendo: 1 paciente com metástase cerebral, 3 pacientes com tumores de cabeça e pescoço, 9 com câncer de mama e 9 com tumores da próstata. Também foi quantificada a influência da heterogeneidade do tecido irradiado, através dos métodos de correção de heterogeneidade do XiO. Independentemente da correção de heterogeneidade do tecido, de um modo geral, o algoritmo de Convolution tendeu a subestimar a dose no PTV quando comparado com os outros dois algoritmos de cálculo de dose. Não foram percebidas diferenças significativas nos valores de dose de radiação calculados para o PTV, determinadas com os outros dois algoritmos, no entanto, o método Superposition proporciona leve redução do tempo de processamento computacional. O trabalho pretende contribuir para uma melhor compreensão da sistemática de cálculo do TPS XiO e assim, beneficiar os usuários dos planejamentos computadorizados durante a análise dos indicadores da qualidade do plano de tratamento.<br>This paper bring forward a study of radiotherapeutic planning accomplished by XiO 5.10 treatment planning systems utilized in radiotherapic centers. The clinical protocols of radiotherapy were analyzed through bibliographic research in scientific articles and texts produced by societies related to the area of radioncology. . Technical reconnaissance visits were performed in radiotherapy services for a better understanding of the differences between the systems of radiotherapy planning applied. The research verified the response of three distinct computational algorithms of calculation of dose radiation: Superposition, Convolution and Fast Superposition, available in the Tps XiO® of Elekta Medical Systems. For this purpose, were analyzed the dose distribution parameters for 22 radiotherapy plans performed in a private radiotherapy clinic: 1 patient with cerebral metastasis, 3 patients with head and neck tumors, 9 with breast cancer and 9 with prostate tumors . The influence of the heterogeneity of the irradiated tissue was also quantified through the XiO heterogeneity correction methods. Regardless of the correction of tissue heterogeneity, the Convolution algorithm tended to, in general, underestimate the dose in the PTV when compared to the other two dose calculation algorithms. No significant differences were observed in the radiation dose values calculated for the PTV, determined with the other two algorithms, however, the Superposition method provides a slight reduction of computational processing time. This paper aims to contribute to a better understanding of the systematics of TPS XiO calculation and thus, to benefit the users of the computerized planning during the analysis of the quality indicators of the treatment plan.<br>empresa privada
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Sandberg, Linnea. "Quality assurance of a radiotherapy registry." Thesis, Umeå universitet, Institutionen för fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-176779.
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The radiotherapy clinics in Sweden have been without a functioning national platform consisting of dose data from patients undergoing radiotherapy. A national collaboration between clinics will improve the quality of radiotherapy since clinics will be able to compare dose data from treatment plans between clinics. It will also help and improve future researches in radiotherapy. A new national quality registry for radiotherapy in Sweden is under development and is located on the INCA platform. The aim of this study is to do a quality assurance of the INCA registry. The data stored in the registry are calculated from the treatment plans stored locally at the clinics. The quality assurance of the registry is done by creating a program run by Python code and by using Streamlit as the graphical user interface. The program takes dose and volume data from the dose volume histograms located in treatment plans from the INCA database and compares it with the dose and volume data from the local clinics' treatment planning system. The different treatment planning systems considered in the program are Oncentra(Elekta, Sweden), Eclipse(Varian, U.S.), RayStation(RaySearch Laboratories, Sweden) and Monaco(Electa, Sweden). The compared absorbed doses are the dose to 99% of the structure volume(D99%), D98%, D50%, D2% and D1%. The program generates how much the INCA data differs from the TPS data in percent and is named QARS(Quality Assurance of the Radiotherapy Database in Sweden). A verification of the created program and a preliminary evaluation is done on a limited dataset containing three patient groups(prostate patients, lung patients and head and neck patients) with five patients in each group. The dataset is run through the program with patient data from both Oncentra and Eclipse. The result indicates that all the near-maximum doses, D2% and D1% in INCA are very close to their corresponding TPS dose. There is a more noticeable difference in the near-minimum doses, D99% and D98% but also for some D50% where the difference seems to increase in larger structure volumes with very low doses and in very small structure volumes, smaller than 0.01 cm3. It is compared how well INCA agrees with Oncentra and Eclipse respectively and it is clear that Eclipse has a smaller difference to INCA than Oncentra for structures with very small volumes and larger structures with low doses. To summarise the study, it generates a program for quality assurance of the national quality registry for radiotherapy in Sweden which hopefully can help improve the quality of radiotherapy and help future researches in the field.
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Persson, Ida Maria Linnéa. "Designing a Sustainable System for Water Supply and Sanitation in Rural Peru." Thesis, Uppsala University, Department of Earth Sciences, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-111152.
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<p>Given the tremendous importance of water supply and sanitation (WSS) on health and welfare, the purpose of this thesis was to suggest a design of a sustainable WSS system for a rural village in the sub-Andean Amazon of Northern Peru. WSS planning and intervention in the developing world have traditionally been characterized by large failures, and to understand the related problems, this work was initiated with a literature review on the topic. The review resulted in the development of a planning support, containing eight stages ranging from project identification to project realization. Within this thesis, the first four stages were implemented, including an in-field WSS situation assessment and a screening of suitable technical options.</p><p>The in-field assessment contained a general fact collection, an inventory where about a fifth of the households in the village was visited and interviewed, and a water quality analysis. An analysis of the assessment findings resulted in the identification of the WSS components requiring intervention. Thereafter followed a screening of suitable technologies, and based on the results from the analysis, a selection of interesting options was done. Selected options were reviewed and evaluated according to a set of sustainability criteria.</p><p>A majority of the households in the village had standpipes on their premises, delivering untreated water from an unprotected creek outside the village. Apart from surface water, rainwater and water from an open spring were also used in the village. The water analysis revealed that surface water contained elevated levels of bacteria, whereas the spring water was clean. Contaminated water remained contaminated after household treatment (boiling), indicative of poor handling. Water treatment with solar disinfection (SODIS) proved to be effective. The sanitary situation was not satisfactory; almost all households had unimproved pit latrines that could not ensure a hygienic separation of excreta, and open defecation was also practiced. Greywater, resulting from showering and cloth-washing under the standpipe, was at best diverted away from the premises by small drains, but often not managed at all. Stormwater created unhygienic conditions on both private premises and in communal areas during the rainy season; the management situation was similar to that of greywater. Solid waste was not officially managed and even though many of the households had designated a collection site, waste was commonly seen all over the premises.</p><p>The selected technologies were mainly inexpensive such that could be constructed, operated and managed by the community itself. From the assessment it also became clear that the WSS situation could be considerably improved by behavior change. Following the developed planning support; with the finalization of this thesis, the next step would be to present the results from the screening and evaluation of technologies to the villagers, for them to decide which options to proceed with.</p><br><p>Debido a la gran importancia del agua potable y saneamiento (APS) para la salud y el bienestar, el objetivo de este proyecto fue proponer un sistema APS, adecuado y sostenible, para una aldea rural en la selva Amazónica en el norte de Perú. Tradicionalmente, la planificación y el diseño de APS en el mundo en desarrollo han sido caracterizados por fallos grandes, y para comprender los problemas, este trabajo comenzó con un estudio amplio sobre el tema. El estudio resultó en un apoyo de planificación, que contiene ocho etapas que van desde la identificación de un proyecto a la realización del proyecto, y fue empleado para la orientación en el trabajo posterior. Dentro de esta tesis, las primeras cuatro etapas se llevaron a cabo, incluyendo una evaluación de la situación APS en campo y un examen de las opciones técnicas adecuadas.</p><p>El trabajo de campo incluía una colección de datos, un inventario, en el que una quinta parte de los hogares en el pueblo fue visitada y entrevistada, y un análisis del agua. Un análisis de los resultados del trabajo de campo resultó en la identificación de los componentes de APS que requieren una intervención. Después siguió un examen de tecnologías adecuadas, y con base en los resultados del análisis se hizo una selección de opciones interesantes. Las opciones seleccionadas fueron revisadas y evaluadas de acuerdo a un conjunto de criterios de sostenibilidad.</p><p>En la mayoría de los hogares del pueblo había una pileta en sus parcelas, entregando agua no tratada de una quebrada sin protección, a fuera del pueblo. Aparte de las aguas superficiales, habían aguas de lluvia y de una fuente abierta. El análisis del agua mostraba niveles elevados de contaminación bacteriológica en las aguas superficiales, mientras que el agua de la fuente abierta era limpia. El tratamiento del agua con la desinfección solar fue demostrado ser eficaz. La situación sanitaria no era satisfactoria – casi todos los hogares tenían letrinas de foso, que no podían asegurar una separación higiénica de la excreta, y la práctica de defecación al aire libre también se veía. Aguas grises, resultante del lavado de ropa y el baño de personas debajo de la pileta, en el mejor de los casos estaban desviando de las parcelas, pero a menudo no estaban tratando. Durante las épocas de lluvia, había bastantes problemas con el agua de escorrentía, creando las condiciones antihigiénicas, y el manejo de la situación era la misma que la de las aguas grises. Los residuos sólidos no estaban oficialmente manejados y aunque muchos de los hogares habían designado un lugar especial en el patio para su recolección, eran comúnmente vistos en todas las parcelas.</p><p>Las tecnologías seleccionadas fueron tales que podrían ser financiadas, construidas, operadas y administradas por la propia comunidad. La evaluación reveló que la situación también podría mejorar considerablemente con un cambio de conducta. A la finalización de este proyecto, la siguiente etapa, de acuerdo con el apoyo de la planificación, sería devolver la evaluación de las opciones seleccionadas a los habitantes del pueblo, y dejar a ellos decidan con cuales opciones quieren proceder.</p><br><p>Dricksvatten och sanitet (DVS) är extremt viktigt för hälsa och välfärd, både för individen och för samhället i stort. Syftet med detta examensarbete var därför att föreslå en utformning av ett hållbart DVS-system för en by i sub-andinska Amazonas i norra Peru. DVS-planering och -projektering har traditionellt karakteriserats utav stora misslyckanden, och för att förstå denna problematik så inleddes arbetet med en översiktlig studie i ämnet. Detta resulterade i att ett vägledande planeringsstöd utvecklades, bestående av åtta steg som sträcker sig från problemidentifikation till projektrealisering. Inom ramen för detta arbete ingick de fyra första stegen, vilket inkluderade en fältundersökning av DVS-situationen i byn och en genomgång av lämpliga tekniska alternativ.</p><p>Fältundersökningen innefattande en allmän faktainsamling, en inventering där en femtedel av byns hushåll besöktes och intervjuades, och en vattenanalys. Resultaten från fältundersökning sammanfattades och ett antal DVS-punkter identifierades som i behov av åtgärder. I teknikgenomgången användes resultaten från fältundersökning som grund för urvalet av intressanta alternativ, vilka sedan utvärderades utifrån en uppsättning hållbarhetskriterier.</p><p>Majoriteten av hushållen i byn hade en vattenkran på sina ägor, och vattnet levererades obehandlat från ett oskyddat vattendrag utanför byn. Förutom ytvatten så använde man även regnvatten och vatten från en öppen källa. Vattenanalysen visade att ytvattnet var starkt förorenat av bakterier, medan källvattnet visade sig vara rent. Förorenat vatten förblev förorenat även efter att hushållen behandlat det (genom kokning), vilket tyder på dålig efterhantering. Soldisinfektion (SODIS) visade sig vara en effektiv reningsmetod. Den sanitära situationen var otillfredsställande – nästan alla hushåll använde sig av oförbättrade grävda latriner och även tarmtömning i det fria praktiserades. BDT-vatten, från dusch och tvätt under vattenkranen, var som bäst avlett från ägorna med enkla fåror, men oftast inte alls hanterat. Under regnperioden orsakade dagvatten ohygieniska förhållanden och hanteringen var liknande den för BDT-vattnet. Det fanns ingen officiell sophantering och även om många hushåll avsatt en speciell plats på gården för insamling så var nedskräpningen omfattande.</p><p>Utvalda tekniker var främst sådana som skulle kunna bekostas, konstrueras, drivas och skötas av samhället själv. I fältundersökningen framkom det också att situationen skulle kunna förbättras avsevärt genom beteendeändringar. I och med avslutningen av detta arbete är nästa steg att, i enlighet med planeringsstödet, presentera resultaten från utvärderingen av de tekniska alternativen för invånarna i byn, och låta dem besluta om vilka som de vill gå vidare med.</p>
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Martínez, Rovira Immaculada. "Monte Carlo and experimental small-field dosimetry applied to spatially fractionated synchrotron radiotherapy techniques." Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/81470.
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Two innovative radiotherapy (RT) approaches are under development at the ID17 Biomedical
Beamline of the European Synchrotron Radiation Facility (ESRF): microbeam radiation
therapy (MRT) and minibeam radiation therapy (MBRT). The two main distinct characteristics
with respect to conventional RT are the use of submillimetric field sizes and spatial
fractionation of the dose. This PhD work deals with different features related to small-field
dosimetry involved in these techniques. Monte Carlo (MC) calculations and several experimental
methods are used with this aim in mind. The core of this PhD Thesis consisted of the
development and benchmarking of an MC-based computation engine for a treatment planning
system devoted to MRT within the framework of the preparation of forthcoming MRT
clinical trials. Additional achievements were the definition of safe MRT irradiation protocols,
the assessment of scatter factors in MRT, the further improvement of the MRT therapeutic
index by injecting a contrast agent into the tumour and the definition of a dosimetry protocol
for preclinical trials in MBRT.
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Nunes, Isabella Paziam Fernandes [UNESP]. "Metodologia para avaliação dos benefícios clínicos e socioeconômicos do uso da técnica de IMRT em tumores da próstata." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153069.
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Previous issue date: 2018-02-23<br>O presente estudo consiste na análise da viabilidade econômica e financeira da implantação da radioterapia de intensidade modulada (IMRT) no tratamento do câncer de próstata e comparar seus benefícios clínicos frente aos procedimentos similares custeados pelos sistemas de saúde públicos e privados. Para tanto, foram analisadas as distribuições de dose de radiação preconizadas nos planejamentos radioterápicos com as técnicas de radioterapia conformacional tridimensional (3D-CRT) e de intensidade modulada (IMRT), prescrita para 20 pacientes com câncer de próstata tratados em um serviço de radioterapia privado. Para verificação da qualidade da distribuição de dose de radiação no volume de tratamento, foram analisados os índices de homogeneidade (IH) e de conformidade (IC) de cada um dos planos radioterápicos estudados. Em comparação com a técnica 3D-CRT, a técnica de IMRT permitiu uma melhor cobertura e conformação da dose prescrita no volume alvo de planejamento (PTV), porém distribuída de forma mais heterogênea. Além disso, avaliou-se os custos financeiros para aquisição dos equipamentos de irradiação e manutenção dos tratamentos, bem como os valores de repasses feitos pelos sistemas de saúde para os procedimentos de radioterapia em próstata.<br>The present study consists in analyzing the economic and financial viability to establish the intensity modulated radiotherapy (IMRT) in the treatment for prostate cancer and compare its clinical benefits to similar procedures funded by public and private health systems. In order to do so, the radiation absorbed-dose distributions recommended in the radiotherapy plans with three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) techniques, prescribed for 20 patients with prostate cancer treated in a private radiotherapy clinic, were evaluated. To verify the quality of the radiation dose distribution in the treatment volume, the homogeneity index (HI) and the conformity index (CI) of each radiotherapy plans studied were analyzed. In contrast to the 3D-CRT technique, the IMRT technique allowed a better coverage and conformation of the radiation dose prescribed in the planning target volume (PTV), but distributed in a more heterogeneous way. It was also evaluated the financial costs for the acquisition of the irradiation equipment and for the maintenance of the treatments, as well as the values of the on-lending made by the health systems for the radiotherapy procedures for the prostate.
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Nunes, Isabella Paziam Fernandes. "Metodologia para avaliação dos benefícios clínicos e socioeconômicos do uso da técnica de IMRT em tumores da próstata." Botucatu, 2018. http://hdl.handle.net/11449/153069.
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Orientador: Marco Antônio Rodrigues Fernandes<br>Resumo: O presente estudo consiste na análise da viabilidade econômica e financeira da implantação da radioterapia de intensidade modulada (IMRT) no tratamento do câncer de próstata e comparar seus benefícios clínicos frente aos procedimentos similares custeados pelos sistemas de saúde públicos e privados. Para tanto, foram analisadas as distribuições de dose de radiação preconizadas nos planejamentos radioterápicos com as técnicas de radioterapia conformacional tridimensional (3D-CRT) e de intensidade modulada (IMRT), prescrita para 20 pacientes com câncer de próstata tratados em um serviço de radioterapia privado. Para verificação da qualidade da distribuição de dose de radiação no volume de tratamento, foram analisados os índices de homogeneidade (IH) e de conformidade (IC) de cada um dos planos radioterápicos estudados. Em comparação com a técnica 3D-CRT, a técnica de IMRT permitiu uma melhor cobertura e conformação da dose prescrita no volume alvo de planejamento (PTV), porém distribuída de forma mais heterogênea. Além disso, avaliou-se os custos financeiros para aquisição dos equipamentos de irradiação e manutenção dos tratamentos, bem como os valores de repasses feitos pelos sistemas de saúde para os procedimentos de radioterapia em próstata.<br>Mestre
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Marusic, Tibor. "Ray Cast/Dose Superposition algorithm for proton grid therapy." Thesis, Stockholms universitet, Medicinsk strålningsfysik (tills m KI), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-148174.
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Purpose: To develop a Ray Cast/Dose Superposition (RC/DS) algorithm for proton grid therapy. Its functionality needed to include automatic positioning of small proton pencil beams in a grid-pattern and superimposing thin beam Monte Carlo (MC) dose distribution data on a Computer Tomography (CT) density volume. The purpose was to calculate and store un-weighted volumetric dose distributions of individual proton energies for subsequent optimization. Materials & Methods: Using the programming language Python 3.6, CT and Volume Of Interest (VOI) data of various patients and phantoms were imported. The target VOI was projected to either two or four planes, corresponding to the number of used gantry positions. Rays were then traced through the CT voxels, which were converted from Hounseld Units to density using a look up table, to calculate Water Equivalent Distance and proton energy needed to reach the proximal and distal edge of the target volume. With automated grid-pattern beam positioning, thin beam MC calculated depth dose distribution files were interpolated, scaled and superimposed on the CT volume for all beamlet positions. The algorithm reliability was tested on several CT image sets, the proton range estimation compared to a commercial TPS and the depth dose interpolation analyzed using MC simulations. Results: The RC/DS algorithm computation time was on average around 6 hours and 30 minutes for each CT set. The dose distribution output visually conformed to target locations and maintained a grid pattern for all tested CT sets. It gave unwanted dose artifacts in situations when rays outside the beamlet center passed a significant length of low/high density regions compared to the center, which yielded dose distributions of unlikely shape. Interpolating MC dose distribution values showed comparability to true MC references of same energy, yielding results with 0.5% difference in relative range and dose. Conclusions: The developed algorithm provides unweighted dose distributions specific for small beam proton grid therapy and has been shown to work for various setups and CT data. Un-optimized code caused longer computation times then intended but was presumed faster than MC simulations of the same setup. Efficiency and accuracy improvements are planed for in future work.<br>Proton grid therapy group
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Garnier, Nicolas. "Simulation d’un accélérateur linéaire d’électrons à l’aide du code Monte-Carlo PENELOPE : métrologie des traitements stéréotaxiques par cônes et évaluation de l’algorithme eMC." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4241/document.
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L’accélérateur linéaire d’électrons du Centre Hospitalier Princesse Grace a été simulé à l’aide du code Monte-Carlo PenEasy. Après avoir validé l’ensemble des techniques permettant d’accélérer le temps de calcul (réduction de variance, parallélisation, …), les caractéristiques des faisceaux initiaux d’électrons ont été déterminées pour une énergie photons et quatre énergies électrons afin d’étudier deux problématiques cliniques. La première concerne l’étude comparative des réponses de huit dosimètres pour la mesure des données de base en mini-faisceaux à l’aide de cônes stéréotaxiques de diamètres compris entre 30 mm et 4 mm. Ces faisceaux de photons sont caractérisés par de forts gradients de dose et un manque important d’équilibre électronique latéral, ce qui rend les techniques dosimétriques conventionnelles inadaptées. Des mesures de facteurs d’ouverture collimateur (FOC), de profil de dose et de rendement en profondeur ont été réalisées avec sept détecteurs actifs (diodes, chambres d’ionisations et MicroDiamond) et un détecteur passif (film radiochromique) et comparées avec les résultats issus de la simulation Monte-Carlo considérée comme notre référence. Pour la mesure du FOC, seul le film radiochromique est en accord avec la simulation avec des écarts inférieurs à 1 %. La MicroDiamond semble être le meilleur détecteur actif avec un écart maximal de 3,7 % pour le cône de 5 mm. Concernant les mesures de profils de dose, les meilleurs résultats ont été obtenus avec le film radiochromique et les diodes blindées ou non (écart de pénombre inférieur à 0,2 mm). Pour les rendements en profondeur, l’ensemble des détecteurs utilisés sont satisfaisants (écart de dose absorbée inférieur à 1 %). La deuxième application concerne l’évaluation de l’algorithme de dépôt de dose électron eMC sur des coupes scanographiques. Pour cela, un programme de « voxélisation » sous MATLAB a été développé afin de transformer les nombres Hounsfield issus du scanner en propriété de matériau (densité et composition chimique) utilisable par le code Monte-Carlo PenEasy. Une triple comparaison entre la mesure avec films radiochromiques, le calcul avec l’algorithme eMC et la simulation Monte-Carlo PenEasy a été réalisée dans différentes configurations : des fantômes hétérogènes simples (superposition de plaques de différentes densités), un fantôme hétérogène complexe (fantôme anthropomorphique) et une comparaison sur patient. Les résultats ont montré qu’une mauvaise affectation d’un matériau du milieu provoque un écart de dose absorbée localement (jusqu’à 16 %) mais aussi en aval de la simulation du fait d’une mauvaise prise en compte de la modification du spectre électronique. La comparaison des distributions de dose absorbée sur le plan patient a montré un très bon accord entre les résultats issus de l’algorithme eMC et ceux obtenus avec le code PenEasy (écart < 3 %)<br>Using the PenEasy Monte-Carlo code was simulated the linear electron accelerator of Princess Grace Hospital Center. After the validation of all the techniques allowing to accelerate the calculation time (variance reduction technique, parallelization, etc.), the characteristics of the initial electron beams were determined for one photon energy and four electron energies in order to study two clinical issues. The first one concerns the comparative study of the responses of eight dosimeters for the measurement of basic data in small fields using stereotactic cones with a diameter between 30 mm to 4 mm. These photon beams are characterized by strong dose gradients and a significant lack of charged particule equilibrium, making conventional dosimetric techniques unsuitable. Output factor measurment (OF), dose profile and depth dose measurements were performed with seven active detectors (diodes, ionization chambers and MicroDiamond) and a passive detector (radiochromic film) and compared with the results from the Monte Carlo simulation considered as our reference. For the OF measurement, only the radiochromic film is in agreement with the simulation with difference less than 1%. The MicroDiamond seems to be the best active detector with a maximum gap of 3.7% for the 5 mm cone. Concerning the dose profile measurements, the best results were obtained with the radiochromic film and diodes shielded or not (penumbre difference of less than 0,2 mm). For depth dose, all the detectors used have good result (absorbed dose difference less than 1 %). The second application concerns the evaluation of the eMC electron deposition algorithm on CT slices. For this, a « voxelisation » program under MATLAB was developed to transform the Hounsfield numbers from the scanner to material property (density and chemical composition) usable by the PenEasy Monte-Carlo code. A triple comparison between measurement with radiochromic films, calculation with the eMC algorithm and Monte-Carlo PenEasy simulation was carried out in different configurations: simple heterogeneous phantom (superposition of plates of different densities), a complex heterogeneous phantom (anthropomorphic phantom) and a patient comparison. The results showed that a wrong material assignment of the medium causes a difference of dose absorbed locally (up to 16%) but also downstream the simulation due to a wrong taking into account of the modification of the electronic spectrum. The absorbed dose distribution comparison on the patient plane showed a very good agreement between the results from the eMC algorithm and those obtained with the PenEasy code (deviation < 3%)
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Caron, Jérôme. "Etude et validation clinique d'un modèle aux moments entropique pour le transport de particules énergétiques : application aux faisceaux d'électrons pour la radiothérapie externe." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0452/document.
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En radiothérapie externe, les simulations des dépôts de dose aux patients sont réalisées sur des systèmesde planification de traitement (SPT) dotés d'algorithmes de calcul qui diffèrent dans leur modélisationdes processus physiques d'interaction des électrons et des photons. Or ces SPT, bien que rapides enclinique, montrent parfois des erreurs significatives aux abords des hétérogénéités du corps humain. Montravail de thèse a consisté à valider le modèle aux moments entropique M1 pour des faisceaux d'électronscliniques. Cet algorithme développé au CELIA dans le cadre de la physique des plasmas repose sur larésolution de l'équation cinétique de transport de Boltzmann linéarisée selon une décomposition auxmoments. M1 nécessite une fermeture du système d'équations basée sur le H-Théorème (maximisationde l'entropie). Les cartographies de dose 1D de faisceaux d'électrons de 9 et 20 MeV issues de M1 ontété comparées à celles issues de codes de référence : macro Monte-Carlo clinique (eMC) et full Monte-Carlo (GEANT-MCNPX) ainsi qu'à des données expérimentales. Les cas tests consistent en des fantômesd'abord homogènes puis de complexité croissante avec insertion d'hétérogéenéités mimant les tissus osseuxet pulmonaire. In fine, le modèle aux moments M1 démontre des propriétés de précision meilleures quecertains algorithmes de type Pencil Beam Kernel encore utilisés cliniquement et proches de celles fourniespar des codes full Monte-Carlo académiques ou macro Monte-Carlo cliniques, même dans les cas testscomplexes retenus. Les performances liées aux temps de calcul de M1 ont été évaluées comme étantmeilleures que celles de codes Monte-Carlo<br>In radiotherapy field, dose deposition simulations in patients are performed on Treatment Planning Systems (TPS) equipped with specific algorithms that differ in the way they model the physical interaction processes of electrons and photons. Although those clinical TPS are fast, they show significant discrepancies in the neighbooring of inhomogeneous tissues. My work consisted in validating for clinical electron beams an entropic moments based algorithm called M1. Develelopped in CELIA for warm and dense plasma simulations, M1 relies on the the resolution of the linearized Boltzmann kinetic equation for particles transport according to a moments decomposition. M1 equations system requires a closure based on H-Theorem (entropy maximisation). M1 dose deposition maps of 9 and 20 MeV electron beams simulations were compared to those extracted from reference codes simulations : clinical macro Monte-Carlo (eMC) and full Monte-carlo (GEANT4-MCNPX) codes and from experimental data as well. The different test cases consisted in homogeneous et complex inhomogeneous fantoms with bone and lung inserts. We found that M1 model provided a dose deposition accuracy better than some Pencil Beam Kernel algorithm and close of those furnished by clinical macro and academic full Monte-carlo codes, even in the worst inhomogeneous cases. Time calculation performances were also investigated and found better than the Monte-Carlo codes
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Berrios-Ayala, Mark. "Brave New World Reloaded: Advocating for Basic Constitutional Search Protections to Apply to Cell Phones from Eavesdropping and Tracking by Government and Corporate Entities." Honors in the Major Thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1547.
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Imagine a world where someone’s personal information is constantly compromised, where federal government entities AKA Big Brother always knows what anyone is Googling, who an individual is texting, and their emoticons on Twitter. Government entities have been doing this for years; they never cared if they were breaking the law or their moral compass of
human dignity. Every day the Federal government blatantly siphons data with programs from the original ECHELON to the new series like PRISM and Xkeyscore so they can keep their tabs on issues that are none of their business; namely, the personal lives of millions. Our allies are taking note; some are learning our bad habits, from Government Communications Headquarters’ (GCHQ) mass shadowing sharing plan to America’s Russian inspiration, SORM. Some countries are following the United States’ poster child pose of a Brave New World like order of global events. Others like Germany are showing their resolve in their disdain for the rise of tyranny. Soon, these new found surveillance troubles will test the resolve of the American Constitution and its nation’s strong love and tradition of liberty. Courts are currently at work to resolve how current concepts of liberty and privacy apply to the current conditions facing the privacy of society. It remains to be determined how liberty will be affected as well; liberty for the United States of America, for the European Union, the Russian Federation and for the people of the World in regards to the extent of privacy in today’s blurred privacy expectations.<br>B.S.<br>Bachelors<br>Health and Public Affairs<br>Legal Studies
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JIAN, YU-DE, and 簡育德. "Brachytherapy treatment planning system Based on PC." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/72924273282245427642.
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Deng, Rucen. "Spray treatment planning using the ant system Metaheuristic." 2006. http://purl.galileo.usg.edu/uga%5Fetd/deng%5Frucen%5F200608%5Fms.
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WU, RONG-ZHONG, and 吳榮忠. "The study of computer assisted planning system for wastewater treatment plant." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/53607526370200128416.
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Chang, Yuan-Chie, and 張原志. "An online advisory system for wastewater treatment planning of pig farm." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/33166470373883016434.
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碩士<br>國立中興大學<br>畜產學系<br>92<br>The purpose of this study was to develop an online advisory system for wastewater treatment planning of pig farms to provide pig industry to carry on farm’s wastewater treatment planning and consultation on the Internet. This system also assists pig industry to get related knowledge of processing unit before constructing wastewater processing plant and after operation. This system adopted the Windows 2000 Server operation system, and was developed by ASP (Active Server Pages) programming connected with the Microsoft Access Database and executed on web-page through browser (Internet Explorer 5.5 upward). The system collected common wastewater treatment methods in Taiwan and was divided into eight sections concerning process, unit, planning, consultation and related dictionary of wastewater treatment, related websites, user manual and registration system. The planning and consultation of wastewater treatment are mainly focuses in this system. The section of planning of wastewater treatment gives planning and suggestion according to operation scale, land used on wastewater treatment plant, wastewater composition and concentration, estimated quantity of wastewater, treatment efficiency of each wastewater processing unit and effluent standard of wastewater. The section of consultation was divided into three parts in terms of first-class, second-class, and third-class treatments. The treatment methods include three kinds of physical, chemical and biological. The contents of each treatment unit concern collection of unit name, concept of principle and classification, applied characteristics and design condition, treatment matters and suggestion on extraordinary countermeasure. The system uses interactive mode running on the website to assist users to obtain related information about wastewater planning and problem consultation.
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Lin, Lien-Chung, and 林廉鈞. "Using MRI for Dose Calculation in Radiation Treatment Planning System of Brain Tumor." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/68943774987313410133.
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碩士<br>國立清華大學<br>生醫工程與環境科學系<br>95<br>The purpose of this work is to evaluate the practicality of a treatment planning method based only on magnetic resonance imaging (MRI) for radiotherapy. Many investigators have demonstrated that dose escalation with three-dimensional conformal radiation therapy (3DCRT) and intensity-modulated radiation therapy (IMRT) potentially increases the tumor control rate while keeping complication risk at a reasonable level. As dose levels are increased, the precise information of target location and size and the accuracy of dose delivery become crucial. Magnetic resonance imaging (MRI) provides superior image quality for soft-tissue delineation over computed tomography (CT) and is widely used for target and organ delineation in radiotherapy for treatment planning. The main drawback of this modality for treatment planning is the lack of electron density information in the MR images. In this study, we segment two sets MRI images of brain by FCM (fuzzy c-means clustering) method as a target image. To overcome the limitation of MRI in dose calculation, we assigned electron density values to typical anatomical structures. We use the non-linear convert method (Artificial Neural Networks) to transform MRI to Homemade CT (HCT) images. Our results show that the dose differences between HCT images and real CT images are within ±2% in different depths, photon energy, and field sizes. Compared with the homogeneous images, HCT-based treatment planning revealed the more accurate dose and dose distribution. In addition, HCT images can also provide DRR (digitally reconstructed radiograph) for radiography simulation.
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WU, JIA-MING, and 吳嘉明. "The Study of Multi-leaf Collimator Offset Correction in Radiotherapy Treatment Planning System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/24401400278186757450.
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博士<br>義守大學<br>資訊工程學系<br>102<br>We present an analytical and experimental study of split shape dose calculation correction by adjusting the position of the round leaf end position in an intensity-modulated radiation therapy treatment planning system. The precise light field edge position (Xtang.p ) was derived from 50 % of the central axis dose created by nominal light field using geometry and mathematical methods. Leaf position (Xmlc.p), defined in the treatment planning system for monitor unit calculation, could be derived from Xtang.p. Offset (correction) could be obtained by the position corresponding to 50 % of the central axis dose minus the Xmlc.p position. For SSD from 90 cm to 120 cm at 6 MV and 10 MV, the 50 % dose position was located outside of Xmlc,p in the MLC leaf position range of +8 cm to -8 cm. The offset correction increased positively. Whereas the offset correction increased negatively when the MLC leaf position was in the range of -12 cm to -8 cm and +20 cm to +8 cm as the 50 % position was located inside Xmlc,p. The monitor unit calculation could provide under dosage or over dosage of 7.5 % per mm without offset correction. Calibration could be performed at a certain SSD to fit all SSD offset corrections. With careful measurement and an accurate offset correction, it is possible to achieve the dose calculation error within 0.5 % for the adjusted MLC leaf edge location in the treatment planning system.
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Lin, Bor Jyh, and 林柏志. "3D Image Based Computer Assisted Maxillofacial diagnosis, Treatment Planning and Surgical Simulation System." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/54394841374837589386.
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碩士<br>中原大學<br>資訊工程研究所<br>83<br>In this thesis, we have developed a 3D image based
maxillofacial system that can provide the following function:
automatically generating 3D landmarks, measuring based on the
landmarks, suggesting possible model and design operations and
providing 3D sophisticated surgical simulation environment. We
determine the landmarks based on the definitions of 2D
cephalometry. However, we correct the definitions to fit the 3D
volume data. Then, we measure the 3D deviation of landmarks to
compute the maxillary and mandibular deformities. Then, we
provide the treatment suggestion for correcting the
deformities. Precise diagnosis and treatment planning can be
expected by the 3D visible assistance. Our simulation routines
allow the clinician to section the anatomical structure from
various directions and move the sectioned structure to any
place. We compute the new position of soft tissue
simultaneously with the reposition of the hard tissue. Because
of 3D simulation, the clinician can predicate the result of
surgery by computer without manually performing paper surgery
and model surgery.