Дисертації з теми "Cancer Radiotherapy Planning"
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Cheng, Kun. "Deformable models for adaptive radiotherapy planning." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/22893.
Повний текст джерелаGozbasi, Halil Ozan. "Optimization approaches for planning external beam radiotherapy." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34726.
Повний текст джерелаBaustert, Isabelle Catherine. "Quantitative MR imaging in planning and assessing novel cancer treatments." Thesis, Institute of Cancer Research (University Of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248446.
Повний текст джерелаBrown, Elizabeth M. "Biologically guided adaptive radiotherapy treatment planning for virally-mediated head and neck cancer." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/98899/1/Elizabeth_Brown_Thesis.pdf.
Повний текст джерелаWu, Wing-cheung Vincent, and 胡永祥. "Inverse planning in three-dimensional conformal and intensity modulated radiotherapy." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B31246163.
Повний текст джерелаWilson, Elena McNaught. "Three dimensional conformal radiotherapy treatment planning for non-small cell lung cancer." Thesis, University College London (University of London), 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404897.
Повний текст джерелаJagannathan, Rupa. "A case-based reasoning system for radiotherapy treatment planning for brain cancer." Thesis, University of Nottingham, 2013. http://eprints.nottingham.ac.uk/29318/.
Повний текст джерелаNeal, Anthony James. "Optimisation of radiotherapy treatment planning for tumours of the breast, prostate and brain." Thesis, King's College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306922.
Повний текст джерелаJohansson, Jonas. "Comparative Treatment Planning in Radiotherapy and Clinical Impact of Proton Relative Biological Effectiveness." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6593.
Повний текст джерелаZizzari, Angelo. "Methods on tumor recognition and planning target prediction for the radiotherapy of cancer /." Aachen : Shaker Verlag, 2004. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=013333167&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Повний текст джерелаNewbold, Katie Lindsay. "The application of advanced imaging techniques to radiotherapy planning in head and neck cancer." Thesis, Institute of Cancer Research (University Of London), 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498512.
Повний текст джерелаMcGowan, Stacey Elizabeth. "Incorporating range uncertainty into proton therapy treatment planning." Thesis, University of Cambridge, 2015. https://www.repository.cam.ac.uk/handle/1810/248787.
Повний текст джерелаAyles, Michael. "Minimizing errors in treatment planning and delivery during external beam radiotherapy for lung cancer patients." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40731.
Повний текст джерелаDans ce mémoire, une enquête en deux parties à été entreprise pour analyser des méthodes permettant la réduction d’erreurs dans le traitement des cancers pulmonaires. Dans la première partie de l’enquête, nous analysons un système de « feedback » visuel utilisé avec les procédures de « gating » en simulation et en radiothérapie. Ce système a été installé dans la clinique et utilisé par trois patients pendant la radiothérapie et une quinzaine de patients pendant des simulations CTs. Il a ainsi été observé que l’utilisation du « feedback » permettait de régulariser la respiration des patients et ainsi d’optimiser l’utilisation des techniques de « gating » afin de réduire l’effet des mouvements interne des tumeurs durant la thérapie et les simulations. La deuxième partie de l’enquête consistait en une étude retrospective qui avait pour but de permettre la comparaison de plusieurs algorithmes de calcul de dose. Les résultats obtenus à l’aide des algorithmes du système de planification de traitements Eclipse ont été comparés à ceux qui ont été calculés en utilisant les codes Monte Carlos EGSnrc et DOSXYZnrc. Les données de quatre patients souffrant du cancer du poumon qui avaient étés traités avec des faisceaux de photons 18 MV ont ainsi été recalculées. Les résultats obtenus ont démontré que les algorithmes d’Eclipse surestimaient systématiquement les doses à cause de la faible densité des tissus pulmonaires et du manque d’équilibre électronique dû au dimensions des faisceaux.
Perrin, Rosalind Lucy. "The application of PET/CT imaging data to external beam radiotherapy planning in lung cancer." Thesis, Institute of Cancer Research (University Of London), 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.538270.
Повний текст джерелаZizzari, Angelo [Verfasser]. "Methods on Tumor Recognition and Planning Target Prediction for the Radiotherapy of Cancer / Angelo Zizzari." Aachen : Shaker, 2004. http://d-nb.info/1170545556/34.
Повний текст джерелаDella, Gala Giuseppe. "A method for automated generation of radiotherapy treatment plans for lung cancer." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/9549/.
Повний текст джерелаsuh, yelin. "DEVELOPMENT AND INVESTIGATION OF INTENSITY-MODULATED RADIATION THERAPY TREATMENT PLANNING FOR FOUR-DIMENSIONAL ANATOMY." VCU Scholars Compass, 2009. http://scholarscompass.vcu.edu/etd/1827.
Повний текст джерелаSandberg, 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.
Повний текст джерелаKishi, Takahiro. "Comparative evaluation of respiratory-gated and ungated FDG-PET for target volume definition in radiotherapy treatment planning for pancreatic cancer." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225447.
Повний текст джерелаCashmore, Jason. "Operation, characterisation & physical modelling of unflattened medical linear accelerator beams and their application to radiotherapy treatment planning." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4616/.
Повний текст джерелаMondlane, Gracinda. "A comparative treatment planning study of radiotherapy of clinical liver- and stomach-cancer cases with either photon or proton beams." Thesis, Stockholms universitet, Fysikum, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-132177.
Повний текст джерелаMylona, Eugenia. "From global to local spatial models for improving prediction of urinary toxicity following prostate cancer radiotherapy." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S109.
Повний текст джерелаExternal beam radiotherapy (EBRT) is a clinical standard for treating prostate cancer. The objective of EBRT is to deliver a high radiation dose to the tumor to maximize the probability of local control while sparing the neighboring organs (mainly the rectum and the bladder) in order to minimize the risk of complications. Developing reliable predictive models of genitourinary (GU) toxicity is of paramount importance to prevent radiation-induced side-effects, and improve treatment reliability. Urinary symptoms may be linked to the irradiation of specific regions of the bladder or the urethra, in which case the dose received by the entire bladder may not be sufficient to explain GU toxicity. Going beyond the global, whole-organ-based models towards more local, sub-organ approaches, this thesis aims to improve our understanding of radiation-induced urinary side-effects and ameliorate the prediction of urinary toxicity following prostate cancer radiotherapy. With the objective to assess the contribution of urethra damage to urinary toxicity, we propose a multi-atlas-based segmentation method to accurately identify this structure on CT images. The second objective is to identify specific symptom-related subregions in the bladder and the urethra predictive of different urinary symptoms. For this purpose, we propose two methodologies for analyzing the spatial dose distribution; one based on the construction of 2D dose-surface maps (DSM) coupled with pixel wise comparisons and another based on 3D dosevolume maps (DVMs) combined with voxel-wise comparisons. Identified subregions are validated in external populations, opening the perspective for patient specific treatment planning. We also implement and compare different machine learning strategies and data augmentation techniques, paving the way to further improve urinary toxicity prediction. We open the perspective of patient-specific treatment planning with reduced risk of complications
Mu, Xiangkui. "Clinical application of intensity and energy modulated radiotherapy with photon and electron beams." Doctoral thesis, Umeå : Strålningsvetenskaper, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-443.
Повний текст джерелаHargrave, Catriona Elizabeth. "Image acquisition and manipulation protocols for CT-PET fusion to improve the accuracy of gross tumour volume localisation for 3D conformal radiotherapy for lung cancer." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/34465/1/Catriona_Hargrave_Thesis.pdf.
Повний текст джерелаWells, Thomas Peter Edward. "Optimising the therapeutic ratio of adjuvant breast cancer treatments : assessment of chemoradiation heart damage with serum cardiac troponin I and the use of open MRI in adjuvant breast radiotherapy planning." Thesis, University of Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424051.
Повний текст джерелаNunes, 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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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.
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.
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.
Повний текст джерелаResumo: 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.
Mestre
Justino, Pitagoras Baskara. "Utilização da ressonância magnética para o planejamento radioterápico dos tumores de colo de útero." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/5/5151/tde-31052007-164501/.
Повний текст джерелаOBJECTIVES The purposes of this study were to verify the chances of geographic miss in conventional 2-dimensional radiotherapy planning in patients with uterine cervix cancer, by means of magnetic resonance imaging (MRI); to compare the data from FIGO staging system with MRI findings; and to evaluate the influence of contrasted rectum X-ray in predicting geographic miss. MATERIAL AND METHODS: Eighty patients with uterine cervical carcinoma were analyzed. After clinical staging (FIGO), magnetic resonance imaging of the pelvis was performed. The images were compared to the classic 4-field technique (box) of radiotherapy. Geographic miss was considered when the tumor volume was not included in the irradiation fields with at least 1cm margins. Data of physical examination and RM were compared. RESULTS: In 45 (56,2%) of the 80 studied patients, fields? limits were not adequate. The anterior (anterior 1/3 of pubis) and posterior limits (S2-S3) of the lateral fields of irradiation were critical. Great discrepancy was observed when physical exam was compared to MRI findings. In most cases, physical exam tended to under-stage the tumors, mainly due to vaginal and parametrial extension. Tumors with antero-posterior diameter larger than 6cm and volume above 100cm3 presented statistically significant correlation with geographical miss. Displacement of the anterior rectal wall outside the posterior limit of the lateral fields in the contrasted X-ray was also significantly correlated with geographical miss. CONCLUSIONS: MRI findings detected and prevented geographic misses in the majority of the patients. When compared to physical examination, tumor volume and extension were better defined by MRI. In the present study, the evaluation of the anterior rectal wall displacement in the lateral x-ray of the irradiation fields was associated with the risk of geographical miss.
Reuzé, Sylvain. "Extraction et analyse de biomarqueurs issus des imageries TEP et IRM pour l'amélioration de la planification de traitement en radiothérapie." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS341/document.
Повний текст джерелаBeyond the conventional techniques of diagnosis and follow-up of cancer, radiomic analysis allows to personalize radiotherapy treatments, by proposing a non-invasive characterization of tumor heterogeneity. Based on the extraction of advanced quantitative parameters (histograms of intensities, texture, shape) from multimodal imaging, this technique has notably proved its interest in determining predictive signatures of treatment response. During this thesis, signatures of cervical cancer recurrence have been developed, based on radiomic analysis alone or in combination with conventional biomarkers, providing major perspectives in the stratification of patients that can lead to dosimetric treatment plan adaptation.However, various methodological barriers were raised, notably related to the great variability of the protocols and technologies of image acquisition, which leads to major biases in multicentric radiomic studies. These biases were assessed using phantom acquisitions and multicenter patient images for PET imaging, and two methods enabling a correction of the stratification effect were proposed. In MRI, a method of standardization of images by harmonization of histograms has been evaluated in brain tumors.To go further in the characterization of intra-tumor heterogeneity and to allow the implementation of a personalized radiotherapy, a method for local texture analysis has been developed. Specifically adapted to brain MRI, its ability to differentiate sub-regions of radionecrosis or tumor recurrence was evaluated. For this purpose, parametric heterogeneity maps have been proposed to experts as additional MRI sequences.In the future, validation of the predictive models in external centers, as well as the establishment of clinical trials integrating these methods to personalize radiotherapy treatments, will be mandatory steps for the integration of radiomic in the clinical routine
Sun, Aijun. "Radiolabeled acetate PET in oncology imaging studies on head and neck cancer, prostate cancer and normal distribution /." Doctoral thesis, Umeå : Umeå university, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-32980.
Повний текст джерелаChi, Jen-Hung, and 紀任鴻. "Semi-Automated Image Segmentation for Radiotherapy Treatment Planning in Lung Cancer." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/23pkw7.
Повний текст джерела中國醫藥大學
生物醫學影像暨放射科學學系碩士班
105
Radiotherapy is currently one of the main treatment of the cancer. In order to avoid the normal tissue to accept too much radiation, the radiotherapy treatment planning will be designed before clinical radiation therapy. The Radiotherapy treatment planning is usually performed by experienced radiophysicists and oncologists, who are according to personal experience and imaging information, routinely contour organs near the tumor and the treatment range, and this process usually spends a lot of time. We believe that the contours of the organ can be obtained by the result of image segmentation, and if reducing the time of the contouring process during designing the radiotherapy treatment planning can increase the efficiency and reduce the human consumption. We used the random walks algorithm to segment the image, and built a graphical user interface system to assist the user to set seed points, using the random walks algorithm for image segmentation obtained organ contours through the seed points are provided by the user. We contoured the lungs, trachea, heart, spinal cord, body and target tumor volume in the experiment, and compared with the contours of the experts. In our experimental results, the most of the results of each organ in contour cases and clinical cases were good, only slightly higher in the volume of the spinal cord. In the results of the calculus, the average amount of time spent in each study in our study was about two minutes, and it was effectively to save time.
Chanyavanich, V., SK Das, WR Lee, and JY Lo. "Knowledge-based IMRT treatment planning for prostate cancer." Thesis, 2011. http://hdl.handle.net/10161/3879.
Повний текст джерелаDissertation
"Development of adaptive dose constraints templates for dose optimization in intensity-modulated radiation therapy (IMRT) treatment planning advanced-stage nasopharyngeal cancer." Thesis, 2007. http://library.cuhk.edu.hk/record=b6074802.
Повний текст джерелаIn conclusion, the solutions to several major problems in IMRT planning for advanced-stage NPC were investigated and established. It has been demonstrated in this research that, by applying these methods and tools, significant improvement in the dosimetry and efficiency of IMRT treatment planning can be accomplished as compared with conventional IMRT planning techniques. It is expected that such would translate into an improvement in treatment throughput, better tumor control and reduction in normal tissues complications. The methods developed have potential to be applied to all stages of NPC and to other tumor sites.
The first study was to improve the efficacy in target coverage and organs sparing using an "organ-splitting" approach. The OARs which overlapped with targets were split into target-overlapping and non-overlapping segments and each segment was assigned with different constraints parameters to increase the degree of flexibility during optimization. As a result, a steep gradient in the dose distribution at the regions of interface between the targets and normal critical organs could be achieved and treatment quality was improved. In the second study, a thorough dosimetric comparison between conventional 2-dimensional (2D) RT and IMRT plans was conducted to determine, with reference to outcome of 2D treatments, the extended tolerance dose limits for the critical organs, especially that of the brainstem and spinal cord, and their planning organ at risk volume. Such data could then serve as reference in IMRT planning when the dose of critical organs need be exceeded in order to allow adequate dose to a very close by target. In the third study, the feasibility of using interpolated contours for segmentation of targets and OARs in IMRT planning was investigated. The result indicated that the use of interpolated contours in IMRT planning could significantly reduce the contouring time by about 50% without degrading the target coverage and OARS sparing. In the final study, an array of dose constraint templates that could accommodate different degrees of overlap between the targets and OARs, together with a template selection program, were developed to improve the efficiency of IMRT planning. By applying the methods and tools developed, IMRT treatment planning of advanced NPC could become more efficient and less dependent on planner's experience.
Chau, Ming Chun.
Adviser: Anthony Chan Tak Cheung.
Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 0948.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (leaves 118-128).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract also in Chinese.
School code: 1307.
HUANG, KAI-JUN, and 黃凱俊. "Analytical Platform Design of Second Cancer Risk Probability for Treatment Planning in Radiotherapy." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/9nbeef.
Повний текст джерела國立高雄應用科技大學
電子工程系碩士班
104
Purpose: Currently, analysis of second cancer risk (SCR) induced radiation dose in radiotherapy is quite important but is also not convenient. This study develops a quick, convenient, simple analysis platform of SCR with the models of risk analysis. Materials and methods: In this study, the graphical user interface (GUI) in Matlab and risk equivalent dose (RED) response curve published Schneider et al. in 2011 are used to develop the user-friendly operating platform. According to fractionation effects and cell repopulation, RED response curve can be divided into linear model, linear-exponential model and plateau model. Three models calculate individual organ equivalent dose (OED), and estimate excess absolute risk (EAR) and lifetime attributable risk (LAR). The RANDO phantoms of whole body irradiation are used to simulation analysis the therapy-induced second cancer risks of breast cancer of female and nasopharyngeal cancer of male. Results: In the present study, SCR of platform designs graphical buttons to operate easily for users. In order to operate fast and simply, functions of platform are data loading, input of basic information (age, sex, organ, classification of tissues, etc.), estimation of risks of second cancer and output of result. Because supporting windows operating system, the system of SCR can be popularly applied to the general computers, and can be used to enhance convenience of research in future. Besides, the simulation results of EAR of patients of ipsilateral breast are 183.11, 43.52 and 50.71 people per million in linear model, linear-exponential model and plateau model, respectively. In the simulation results of patients of nasopharyngeal cancers, the EAR of second cancers induced in different organs are ten or less people per ten million in linear-exponential model and plateau model except the overestimation of linear model is potential. Conclusions: This study develops a fast, convenient, simple-operated platform which analyzes probability of second cancers. Not only can doctors and researchers use it and the dose-volume histogram (DVH) provided by treatment systems of hospitals to estimate the excess absolute risk (EAR) and lifetime attributable risk (LAR), but they also make treatment plans of patients perfect. Finally, patient’s the quality of life (QoL) can be improved by this platform.
Sun, Jidi. "Development of magnetic resonance imaging based prostate treatment planning." Thesis, 2015. http://hdl.handle.net/1959.13/1308318.
Повний текст джерелаRadiotherapy is one of the main methods used to treat prostate cancer. Radiotherapy treatment relies on accurate planning and simulation before any radiation is administered. Currently this is mainly based on CT (computed tomography) imaging, although MR (magnetic resonance) imaging provides superior soft-tissue contrast and is therefore often used to assist with accurate organ delineation. The overall treatment planning workflow and performance can be improved if the entire workflow is solely performed using MR images. In order to achieve such MR-only treatment planning, three main challenges need to be overcome: 1) the geometric accuracy of MR images needs to be assured ; 2) the MR simulator needs to be commissioned and evaluated ; 3) electron density information required for dose calculation needs to be generated from MR images. This thesis examines each of these challenges. First, a pelvic shape phantom was used to quantify the geometric distortion arising in prostate treatment. The CT image was acquired as the gold reference and the distortion of the MR image was corrected with the vendor’s built-in algorithm. Using the image registration method, the maximum geometric distortion was reduced from nearly 8 mm to within the radiotherapy tolerance level. Second, commercial radiotherapy-dedicated equipment was implemented on the Siemens Skyra 3 Tesla MR scanner. This involved a hard flat tabletop which mimicked the flat radiotherapy treatment table, and coil mounts to lift the MR coil above the patient’s body and minimise coil-induced disagreement between the MR planning and treatment geometry. A reduction in image quality was observed on the MR simulator, but no clinically significant difference was found in the accuracy of organ delineation. Furthermore, use of the MR simulator eliminated patient positioning error associated with conventional MR scanner design and thus reduced the systematic dosimetric error. The entire workflow of MR-based planning was tested using an anthropomorphic phantom and no significant difference was found between MR- and CT-based plans. Finally, substitute (also known as synthetic or pseudo) sCT images were generated from MR images using a multi-atlas local weighted voting method. Validation was conducted on 39 patients and the sCT images were in high level agreement with the CT images. In summary, MR-based radiotherapy planning for treating prostate cancer has been thoroughly tested and evaluated in this study. This may provide an important stepping stone for the future clinical implementation.
Leong, Weng Chi, and 梁詠慈. "Weekly Planning Evaluation for Postoperative Oral Cancer Patients under Adaptive IMRT and RapidArc Radiotherapy." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/09124232435790925710.
Повний текст джерела長庚大學
醫學影像暨放射科學系
101
With advances of modern radiotherapy techniques, effectiveness of radiation therapy is receiving wide attention. Seven postoperative oral cancer patients were enrolled into this study to explore dose variation due to weekly organ volume change under fractionated treatment scheme. The study also evaluated weekly treatment plans under the adaptive IMRT and the RapidArc re-planning protocols. An initial treatment plan generated using the pre-treatment CT image set of a patient was re-assigned to the sequential weekly CT image sets for dose recalculation, to evaluate dose differences between the planned and presumedly delivered dose distributions. In addition, adaptive weekly IMRT and RapidArc plans on the weekly CT image sets were performed. Consequently, dose differences between the existing treatment protocoland the adaptive re-planning protocols were evaluated. Results showed that no matter for the existing or the adaptive treatment protocols, their weekly CTV target doses did not result in significant difference. For the existing treatment protocol, weekly doses to critical organs such as the brain stem, spinal cord and parotid glands increased significantly. This dose increases can be improved to within the dose tolerance levels with the adaptive re-planning strategy. Finally, due to the small number of study subjects, no statistical evaluation is attempted.
THAN, VAN-VIET, and 申文越. "The Evaluation of Differences of 3D-CRT, IMRT and VMAT Radiotherapy Planning for Prostate Cancer." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/5u368u.
Повний текст джерела元培醫事科技大學
醫學影像暨放射技術系碩士班
107
Abstract Purpose: Nowadays, radiation therapy comes to the standard treatment for prostate cancer. There are many critical Organ at Risks (OARs) can be affected during and after the treatment, which can negatively affect patients’ later life. In our study, we made comparisons in terms of the optimal dose to target as well as sparing dose to OARs among three techniques 3D-CRT, IMRT and VMAT in late stage (T3, T4) of prostate cancer. Materials and Methods: Ten late-stages (T3-T4) of prostate cancer patients after being treated by IMRT 5-7 fields were recruited and their CT simulation data formed two more planning: 3D-CRT and VMAT technique. Treatment plan system is Philips Healthcare. The dose influence in PTV was evaluated by Homogeneity index (HI) and Conformation index (CI). Simultaneously, we compared the dose in OARs among three planning methods. All data analyzed with SPSS version 20 by Paired samples T-test to find the statistical significance of each factor. Results: Three treatment planning met the target coverage (over 95% prescription) and dose distribution. However, IMRT and VMAT showed the optimal dose in mean dose in the target, p<0.05. Besides, distribution dose in OARs of IMRT and VMAT was significantly lower comparing with 3D-CRT planning, p<0.05. MU of IMRT (793.4±37.2) planning illustrated higher than 3D-CRT (305.5±19.80) and VMAT (483.8±21.3). VMAT planning was successful in reducing MU and treatment time. Conclusion: Our study demonstrated that VMAT planning was significantly better in planning quality compared with 3D-CRT and IMRT in the optimal dose to target, OARs and treatment time. Keywords: PTV, OARs, Prostate cancer, Dosimitry, 3D-CRT, IMRT and VMAT.
Wang, Yao-Ching, and 王耀慶. "The clinical application of 4D 18F-FDG PET/CT on gross tumor volume delineation for radiotherapy planning in esophageal squamous cell cancer." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/11810074460556438039.
Повний текст джерела中國醫藥大學
臨床醫學研究所碩士班
99
Purpose: Studies suggested PET overlay on CT has shown to have some impact on the definition of the gross tumor volume (GTV), decrease inter-observer variability and change the treatment planning. Organs or tumor motion always influenced the accuracy and quality of CT images in the thoracic malignancy, including esophageal cancer during free breathing cycle. To estimate the feasibility of the combined four-dimensional computed tomography with four-dimensional 18F-fluorodeoxyglucose positron emission tomography (4D PET/CT) in GTV delineation of esophageal cancer. We hypothesized that some standards can be obtained when defining GTV for esophageal cancer by using biological target volume from 4D-PET/CT images. Methods and Materials: This study was a prospective analysis, approved by local institutional review board (DMR98- IRB-171-1 and DMR98- IRB-171-2), of 4D-PET/CT in radiotherapy planning of esophageal cancer. Patients with histologically approved esophageal cancer who would undergo definitive radiotherapy, concurrent chemoradiotherapy or radical surgery were eligible for this study. Eighteen patients with esophageal squamous cell cancer were enrolled between December 2009 and January 2011. Each of them was administered intravenously with 370 MBq (10 mCi) of 18F-FDG and rested supine in a quiet and dimly room. Patients were positioned and simulated in a radiotherapy planning position using the Real-time Position Management system respiratory gating hardware (Varian Medical Systems Inc). Four-dimensional CT images with 2.50-mm slice thickness, and 4D PET images with two table positions, 7 minutes per position, were acquired. All phases of CT images and PET images were automatically fused for this gating study. In 4D images during respiratory cycle, an average phase of CT images was fused with average phase of FDG PETs for analysis of optimal threshold or standardized uptake values (SUV). PET-based GTV (GTVPET) was determined with 8 different threshold methods by autocontouring function at the AW workstation (Advantage SimTM 7.6.0, GE, Healthcare): SUV15%, SUV 2, SUV 2.5, SUV 20%, SUV 25%, SUV 30%, SUV 40% and SUV 50%. The information of tumor extent from the contrast CT scan, panendoscopy and endoscopic ultrasonography (EUS) were used when delineating the CT-based GTV (GTVCT). Excluding the adjacent metastatic lymph nodes, the volume of GTVCT was contoured as a reference tumor volume. To reduce inter-observer variations, at least 2 different radiation oncologists carried out the contouring of the tumors for each patient. GTVPET was compared with GTVCT by volume ratio (VR) and conformality index (CI). CI is the ratio of the volume of intersection of two volumes compared with the volume of union of the two volumes under comparison. VR is the ratio of two volumes, and the denominator is the volume of GTVCT. A suitable threshold level could be defined when GTVPET was observed to be the best fitness of the length, CI or VR from the GTVCT. Results: Automatic co-registrations of 4D CT-FDG PET were successful in 12 patients with 13 GTVCT. The fused images were not available in the other 6 patients. The median age was 48.5years (range, 38-76 years). All patients were men. Eleven lesions (85%) were T3 and T4 stage. EUS was performed for 9 patients (75%). The mean length of GTVCT was 5.73 ± 2.40cm (range, 1.75-10.01cm). The mean volume of GTVCT was 29.41 ± 19.14mL (range, 3.65-70.76 mL). The mean SUVmax was 13.26 ± 2. 78 (range, 9.4-16.9). The decision coefficient (R2) of tumor length difference at the threshold levels of SUV2.5, SUV20% and SUV25% were 0.79, 0.65 and 0.54, respectively. The mean VR ranged from 0.30 to 1.48 (0.86±0.24). The optimal VR, 0.98, close to 1, was at SUV 20% or SUV 2.5. All SUV thresholds compare with SUV 2.5, the p values of SUV15%, SUV40% and SUV50% are 0.007, 0.002, and 0.000, respectively. The mean CI ranged from 0.28 to 0.58. The best fitness for CI was at SUV 20% (0.58 ± 0.10) or SUV 2.5 (0.57 ± 0.13). All SUV thresholds compare with SUV20%, the p values of SUV40% and SUV50% are 0.014, and 0.000, respectively. Conclusions: This study demonstrated that 4D-PET/CT is applicable when contouring the GTV in radiation planning for esophageal cancer. The use of threshold levels of SUV 20% or SUV 2.5 achieves the optimal correlation with tumor length, VR and CI. To assess final treatment outcome, the benefits of RT planning using 4D-PET/CT need more clinical investigations.
Ting, Hui-Min, and 丁慧敏. "Development of a Clinical Decision Analyzing Assistance System Based on the Taguchi-Normal Tissue Complication Probability Architecture for Breast Cancer Radiotherapy Treatment Planning." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/2992n2.
Повний текст джерела國立高雄應用科技大學
電機工程系博碩士班
103
Purpose: To assist the clinical decision making, we aim to develop a radiotherapy treatment planning clinical decision support system. We quantify the influence parameters for different radiotherapy techniques through Taguchi analytic method to investigate the optimal techniques by these parameters in different kind of breast cancer. We also develop an analytic normal tissue complication probability platform for planning evaluation. Materials and Methods: In total 20 early stage breast cancer patients (10-right and 10- left) were enrolled. Five different treatment techniques were used i.e. wedged-tangential fields (WT), intensity modulated radiation therapy (IMRT), hybrid IMRT (H-IMRT), volumetric modulated arc therapy (VMAT), and an innovative hybrid VMAT (H-VMAT) technique we proposed. Using the Taguchi analysis method to analysis the optimal influence parameters for corresponding technique with modified planning quality index (mPQI). With the optimal influence parameters, we compared different techniques in different breast cancer patients. In sequential right or left breast cancer, WT, IMRT, H-IMRT, VMAT and H-VMAT techniques comparison were made. In simultaneous integrated boost right or left breast cancers, IMRT, H-IMRT, VMAT and H-VMAT techniques comparison were done. In bilateral breast cancers, IMRT and VMAT have been compared. We use multiple quantitative indices, including conformity index (CI), homogeneity index(HI), modified planning quality index (mPQI), equivalent uniform dose (EUD), tumor control probability (TCP), normal tissue complication probability (NTCP), to evaluate these techniques for seeking the optimal techniques in different breast cancer treatment for clinical decision support.delivery efficiency. Results: By using Taguchi analysis method, there are different dominant control parameters in different techniques for breast cancers. The forward adjust process is needed to get better plan quality in WT. 6MV photon energy are suitable in H-IMRT technique in left sequencial mode (SQM) patients and VMAT technique in right SQM patients. For the comparison of 5 techniques in SQM breast cancer, all plans can achieve > 95% coverage in planning target volume (PTV), and the organ at risks (OARs) are better sparing in VMAT technique. For the comparison of 4 techniques in simultaneous integrated boost (SIB) breast cancer, the organ at risk is better sparing in VMAT technique. In bilateral breast cancer patients, VMAT technique has better dosimetric results in PTV or OARs.
Chen, Po-Han, and 陳柏翰. "Quantification of Radiotherapy CT image for Non-Small Cell Lung Cancer: Development of Longitudinal Registration Algorithm and Correlation Analysis of Lung Parenchyma Change and Planning Radiation Dose Distribution." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/yc44w7.
Повний текст джерела國立臺灣大學
醫學工程學研究所
103
Lung cancer is one of the leading cause of cancer deaths worldwide, including Taiwan, across gender. In Taiwan, the male mortality rate of lung cancer is as high as 48.9%. Surgery is the best and effective method in the early stage of the lung cancer. However, only 15% of the diagnosed patients are suitable for early-stage surgery. Surgery only is no longer considered for those being diagnosed at the middle to the late stage. Treatment for patients with middle-stage and late-stage may involve chemotherapy, radiotherapy, or a concurrent chemoradiation therapy. Radiation therapy, which is one of the primary therapeutic approaches for non-small cell lung cancer, is a treatment that uses high-energy rays or particles that destroy lung cancer cells. Radiation-induced lung damage (RILD) is a severe complication of radiotherapy in lung cancer patients that presents as a progressive pulmonary injury affecting prognosis and quality of life in patients. In this study a longitudinal registration algorithm is proposed for evaluating the lung parenchyma change after radiotherapy and the correlation to the given radiation strength and distribution of dosage. The proposed registration algorithm overcomes the large parenchyma change which makes the registration much harder by using anatomical structures around the lung, including using spine for the reference set of rigid registration step; using three anatomical structures: bone structures surface, including sternal, rib and spine, airway wall and surface of lower lung to describe the longitudinal difference of breath holding degree. Reference points are sampled from these three anatomical feature structures for the further step of coherent point set registration. Registered by the proposed longitudinal registration algorithm developed by this study, the correlation of regional dose distribution with longitudinal parenchyma change has been evaluated and obvious parenchyma change in the region of radiation dosage above 22 Gy and in 3~7 month is observed.
Pereira, Mariana Nunes. "In-house Implementation and Validation of the Mid-Position CT approach for the Treatment Planning of Respiration-induced Moving Tumours in Radiotherapy for Lung and Upper abdomen cancer." Master's thesis, 2021. http://hdl.handle.net/10451/52083.
Повний текст джерелаA Radioterapia é uma das modalidades principais para tratamentos de foro oncológico que visa destruir a ação proliferativa das células cancerígenas e reduzir o volume tumoral. A sua ação terapêutica através do uso de radiação ionizante tem, subjacente, a máxima de irradiar o tumor com uma elevada dose, ao mesmo tempo que os órgãos de risco (OARs) adjacentes, são tanto quanto possível protegidos. Quando um tumor se localiza no pulmão ou abdómen superior, como no fígado ou pâncreas, o seu movimento devido à respiração pode alcançar até 4 cm, especialmente na direção crânio-caudal, aumentando as incertezas relativas à posição do tumor. No Centro Clínico Champalimaud (CCC), o planeamento convencional dos tratamentos de radioterapia faz uso de uma tomografia computadorizada (CT) que é adquirida aquando da respiração livre do doente e que, por isso, apresenta geralmente artefactos que podem ser uma fonte de erro durante o planeamento. Nos casos em que o movimento do tumor é considerável, é ainda adquirida uma tomografia computadorizada quadrimensional (4DCT) que consiste entre 8 e 10 CTs que representam fases do ciclo respiratório. Posteriormente, a 4DCT é utilizada para delinear o volume interno do alvo (ITV) que engloba toda a extensão do movimento do tumor. Apesar da estratégia do ITV garantir uma adequada cobertura do volume-alvo, os OARs ficam expostos a doses de radiação desnecessárias e a um maior risco de toxicidade. Este efeito é ainda mais preocupante em tratamentos hipofracionados, onde doses mais elevadas são administradas num número reduzido de frações. Nos últimos anos têm sido desenvolvidas estratégias que visam tornar os tratamentos de radioterapia mais eficazes. Uma delas é a reconstrução de uma CT que representa a posição média do doente ao longo do ciclo respiratório (Mid-P CT). Esta estratégia resulta em volumes de tratamento menores do que a estratégia do ITV, possibilitando o aumento da dose e maior controlo tumoral local. O primeiro passo para a reconstrução do Mid-P CT é o registo deformável de imagens (DIR) entre uma das fases da respiração (uma CT da 4DCT), definida como a fase de referência, e as restantes fases. Deste processo resultam campos vetoriais deformáveis (DVF) que contém informação do deslocamento dos tecidos. Os DVFs são subsequentemente utilizados para transformar cada uma das fases da respiração para a posição média. O método do Mid-P foi implementado com sucesso no Instituto do Cancro Holandês (NKI) em 2008. Apesar dos bons resultados clínicos, o número de centros de radioterapia que utiliza esta técnica é muito reduzido. Tal deve-se, por um lado, à inexistência de soluções comerciais com esta funcionalidade e, por outro, ao esforço necessário alocar para implementar e validar soluções desenvolvidas internamente. O presente projeto teve como principal objetivo implementar a estratégia do Mid-P no CCC (Portugal). Para tal, foi otimizado um módulo – RunMidP – desenvolvido para o software 3D Slicer, que calcula o Mid-P CT e estima a amplitude do movimento do tumor e OARs com base nos DVFs. Considerando que a precisão do módulo e a qualidade de imagem do Mid-P CT devem atender os requisitos para o planeamento em radioterapia, foram realizados testes para validar o módulo. Sempre que possível, a sua performance foi comparada com outras aplicações desenvolvidas para a implementação da técnica do Mid-P, nomeadamente com um protótipo desenvolvido pela empresa Mirada Medical Ltd. (Reino Unido) – Mirada – e com o software desenvolvido no NKI (Holanda) – Wimp. Os testes foram divididos em três estudos diferentes, cada um com um conjunto de dados diferente. No primeiro estudo (estudo A), foram utilizadas 4DCT de 2 fantomas digitais, cuja função respiratória e cardíaca foi modelada de forma simplificada, e de 18 doentes com tumores localizados no pulmão (N = 8), no fígado (N = 6) e no pâncreas (N = 4). Neste estudo, foram comparados dois algoritmos DIR disponíveis no software 3D Slicer, o Plastimatch e o Elastix, em termos da precisão do registo e da qualidade de imagem do Mid-P CT reconstruído. Foi ainda avaliado a capacidade dos softwares RunMidP e Mirada representarem corretamente a posição média do doente e as diferenças das amplitudes do movimento do tumor estimadas pelos dois softwares. No estudo B, foram realizados testes de verificação semelhantes aos supre mencionados, em imagens sintéticas provenientes de 16 doentes, desta vez com a vantagem de se conhecer o “verdadeiro” Mid-P CT e as “verdadeiras” amplitudes do movimento do tumor. Estes foram comparados com os resultados obtidos com os softwares RunMidP e Mirada. Ainda, as unidades de Hounsfield (HU) no Mid-P CT reconstruído por RunMidP e Mirada foram comparadas com as HU na fase de referência, de modo a verificar se os Mid P CTs produziriam diferenças dosimétricas relevantes. No último estudo (estudo C), a qualidade de imagem do Mid-P CT foi avaliada quantitativamente e qualitativamente. Durante a análise qualitativa, foi pedido a dois médicos especialistas que avaliassem a viabilidade dos Mid-P CTs, reconstruídos pelos três softwares (RunMidP, Mirada e Wimp), para o planeamento dos tratamentos. O tempo da reconstrução do Mid-P CT a partir da 4DCT foi de cerca de 1h. Ambos os algoritmos, Plastimach e Elastix, demonstraram ser adequados para DIR de imagens do pulmão e abdómen superior, com diferenças estatisticamente não significativas (p > 0.05) em termos da precisão do registo. Contudo, o Mid-P CT reconstruído com Elastix apresentou uma melhoria na qualidade de imagem, sendo assim o algoritmo DIR escolhido para ser implementado no RunMidP. Em termos de métricas aplicadas a contornos definidos manualmente, tais como a distância de Hausdorf (HD) e coeficiente de Dice (DSC), o erro do registo de imagem foi menor que 1 mm, dentro do contorno do tumor, e 2 mm no pulmão. Os Mid-P CTs reconstruídos com o RunMidP e Mirada apresentaram maiores diferenças, relativamente ao “verdadeiro” Mid-P CT, na região do diafragma e zonas de maior homogeneidade como, por exemplo, no ar presente no intestino. Contudo, para a maioria dos doentes do estudo B, o Mid-P CT reconstruído com o software Mirada apresentou maior índice de similaridade estrutural (SSIM) relativamente ao “verdadeiro” Mid-P CT. Estes resultados podem estar na origem do uso de diferentes algoritmos DIR, mas deveram-se principalmente a uma falha na aplicação das transformações deformáveis pelo módulo RunMiP que foi corrigida posteriormente. Ainda, as diferenças entre as amplitudes estimadas e previstas foram menores que 1 mm para 37 tumores (78,9%), que resultam em diferenças menores que 0.3mm quando convertidas em margens de planeamento. Para além disso, as diferenças nos valores de HU dos Mid-P CTs comparativamente à fase de referência foram, em média, de 1 HU no tumor e OARs. Foram também observadas melhorias na qualidade de imagem do Mid-P CT, nomeadamente um aumento da relação sinal-ruído (SNR) e diminuição dos artefactos. Estes resultados estão de acordo com a avaliação dos médicos que, em geral, consideraram que os Mid-P CTs reconstruídos pelos três softwares são adequados para o planeamento dos tratamentos. No entanto, os Mid-P CTs reconstruídos com dados 4DCT provenientes do CCC apresentaram classificações inferiores aos reconstruídos com dados 4DCT do NKI. Em suma, as modificações do algoritmo DIR Plastimach para Elastix e a correção do método para aplicar as transformações deformáveis, permitiram uma melhoria na qualidade de imagem do Mid P CT e melhor performance do algoritmo, respetivamente. O módulo RunMidP, neste projeto otimizado e validado, apresenta um forte potencial para a reconstrução e implementação da estratégia do Mid-P na clínica, com performance comparável a outras aplicações existentes (Mirada e Wimp). Atenção especial deve ser dada aos dados 4DCT de input que parecem afetar a qualidade de imagem final do Mid-P CT. No futuro, valerá a pena otimizar os parâmetros de aquisição e reconstrução da 4DCT de modo a melhorar a qualidade de imagem e, ainda, o módulo RunMidP pode potencialmente ser otimizado no que respeita ao tempo de reconstrução do Mid-P CT e à precisão do DIR.
Radiotherapy for tumours in the thorax and upper abdomen is challenging since they move notably with breathing. To cover the whole extent of tumour motion, relatively large margins are added to treatment volumes, posing a higher risk of toxicity for surrounding organs-at-risk (OARs). The Mid Position (Mid-P) method accounts for breathing motion by using deformable image registration (DIR) to transform all phases of a 4DCT scan to a time-weighted average 3DCT scan (Mid-P CT). The Mid-P strategy results in smaller treatment volumes, potentially boosting the delivery of hypofractionated treatments. To bring the Mid-P approach to the Champalimaud Clinical Centre (CCC), an in-house Mid position software module – RunMidP – was optimized. The module reconstructs the Mid-P CT and estimates breathing motion amplitudes of tumours and relevant OARs. In addition, this project presents a set of experiments to evaluate the performance of the Mid-P method and its feasibility for clinical implementation. The experiments were conducted throughout three different studies using 4DCT data from 18 phantoms and 23 patients. In Study A, the accuracy and image quality of two DIR algorithms (Plastimatch and Elastix) were assessed using quantitative metrics applied on either warped images or manually delineated contours. The reproduction of the patient’s mean position by the Mid-P CT and the estimation of motion amplitudes were compared to a soon-to-be Mid-P commercial software developed by Mirada Medical Ltd. In Study B,similar experiments were performed, this time using a more rigorous reference – “true” Mid-P CT scans and “true” motion estimations. In Study C, the image quality of Mid P CT scans was assessed quantitatively and qualitatively. Both Plastimatch and Elastix registration showed comparable registration accuracy, although Elastix showed superior image quality of reconstructed Mid-P CTs. Based on contour metrics, the registration error was less than 2 mm. In-house Mid-P CTs showed a slightly lower match to ground truth Mid-P CTs than the ones reconstructed by the Mirada prototype due to differences in DIR methods and small shifts to the original image geometry. Higher image differences were found in the diaphragm lung interface, where the patient's anatomy moves faster due to breathing, and in homogeneous regions such as the air regions in the bowel. On the other hand, differences (estimated-predicted) in motion amplitudes smaller than 1 mm were observed in 37 moving tumours (78.7%), showing a good performance of the Mid-P algorithm. Regarding the image quality, improvements in the signal-to-noise ratio and removal of image artefacts in Mid-P CTs are great advantages for using them as the planning CT. Clinicians also gave a good assessment of the suitability of Mid-P CT scans for treatment planning. No significant differences were found in the performance of the RunMidP compared to other Mid-Position packages, although worse scores were given to the CCC dataset than the dataset from another hospital. The in-house Mid-position algorithm shows promising results regarding the use of the software module in radiotherapy for lung and upper abdomen cancer. Further exploration must be given to improve the registration accuracy, image quality of the input data, and speed up the reconstruction of the Mid-P CT scan.
Γρηγοριάδης, Ηλίας. "Βελτιστοποίηση πλάνου θεραπείας στο μαστό: Field in a Field (FiF) vs. υψηλές ενέργειες φωτονίων". Thesis, 2014. http://hdl.handle.net/10889/8359.
Повний текст джерелаThe purpose of this thesis is to optimize the breast cancer treatment planning for the coplanar tangential fields of 6MV energy. The need for this arose as the dose distribution appears deficient both at the center and deeper in the CTV, as shown in the CT and sagittal images below, whereas the dose is satisfactory distributed at the perimeter of the breast. In order to accomplish that, there were applied 4 radiation techniques: 1. Two coplanar tangential fields of 6MV energy, 2. Two coplanar tangential fields of 15MV energy, 3. Two coplanar tangential fields of 6MV energy with Field in a Field (FiF) of 15MV energy and 4. Two coplanar tangential fields of 6MV energy with two Fields in a Field (FiF’s) of 15MV energy. The method above was applied on 100 patients. 95% of them had T1 tumor (T<2cm), T2 tumor (T=2-5cm) and a number of infiltrated lymph N<3. The equipment that has been used for the materialization of the procedure was: 1. A Computed Tomographer Somatom Duo Siemens, 2. An RVS system of VARIAN, 3. A TPS Eclipse system of VARIAN, 4. A Simulator Aquity of VARIAN and 5. A linear accelerator ELEKTA SL 15. Using the program IBM SPSS 20 (Statistical Package for Social Sciences), for a hundred patients, the statistical analysis showed that the average of the mean dose was 96.5% for the 6MV, 98.9% for the 15MV, 100.7% for the 6MV + 1 FIF of 15MV and 101.9% for the 6MV + 2 FIF of 15MV respectively (95% CI, p<0.001). There was an interaction between CTV size and mean dose, notably for large breasted patients (CTV>750cc). In this particular clinical scenario two 6MV tangential fields with 2 FIFs consistently outperformed the others. Minimum dose was also statistically different among all groups (p<0.05) except for the two FIF-less tangential fields with 6 and 15 MV. Interestingly, minimum dose (%) lacked a dependence on volume size. The result of this procedure was that the mean dose increases from method to method as it was obvious from the statistical analysis. The homogeneity index decreases respectively from method to method which indicates improvement of the dose distribution. It was also proved that, for certain large volumes of CTV the best method was the 6MV with two FIF’s of 15MV energy, whereas for smaller volumes of CTV the other three methods were of the same effectiveness. In conclusion, as far as the organs at risk concern, it has been found that the V20, of the heart and the right or left lung each time, is irrelevant of the technique that has been used each time.
Mathieu, Dominique. "Traitement du cancer pulmonaire non à petites cellules par radiothérapie stéréotaxique d’ablation." Thèse, 2016. http://hdl.handle.net/1866/13873.
Повний текст джерелаLung neoplasia remains the leading cause of cancer death accounting for nearly 6,000 deaths per year in Quebec. In recent years, stereotactic ablative radiotherapy (SABR) has emerged as an alternative treatment to anatomical resection for inoperable patients suffering from early stage non-small cell lung cancer. This technique can deliver highly focused doses such as 30-60 Gy in 1-8 fractions in order to target precisely the treatment volume while sparing healthy tissue. In 2009, the Centre Hospitalier de l’Université de Montréal acquired a robotic SABR apparatus, the CyberKnife™ (CK), a linear accelerator mounted on a moving arm producing non-coplanar photon beams of 6 MV with millimetric precision. This thesis presents two scientific peer reviewed articles adressing some clinical and physical challenges with CK. On one hand, a clinical prospective study reporting the advantages of lung SABR, a technic that offers excellent long-term tumor control and helps maintain the quality of life and lung function. On the other hand, a medical physics study exposing the limits of computed tomography scan acquisition in breath-holding for CK treatment planning.
Lu, Tzu-Ying, and 呂姿瑩. "Simultaneous integrated boost radiotherapy after breast conserving surgery of breast cancer: Treatment plannings comparised of intensity modulated radiotherapy and helical TomoTherapy." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/26674279171162744343.
Повний текст джерела高雄醫學大學
醫學放射技術學研究所
100
Purpose: The purpose of this study is to compare the radiation dose distribution inverse-planned intensity-modulated radiotherapy (ipIMRT) and helical TomoTherapy (HT) for breast cancer patients undergoing whole breast radiation with simultaneous integrated boost (SIB), which may be related to radiation-induced pneumonitis and cardiac mortality. To investigate whether some geometric/dosimetric indicators can be determined to estimate the normal tissue complication probability. Material and methods: Thirty-six patients with left breast cancer (clinical stage T1–2N0–1M0) were eligible for the trial. All patients generated their treatment planning from both HT and ipIMRT under the prescription of SIB technique. The whole breast and tumor bed were prescribed 50.4Gy and 60.2Gy, in 28 fractions, respectively. These parameters include conformity index(CI)、homogeneity index (HI)、different dose point and normal tissue complication probability. And three geometric parameters were measured for each patient: the thorax width/thickness ratio, breast volume and the angle of the nipple–sternum to nipple-chest wall. Results: The HI and CI were better in HT than in ipIMRT (p<0.001), and differenr dose points such as maximum dose、minimum dose and so on were more closer the prescribed dose. But there were more volume received lower dose(Ipsilateral lung V5Gy:HT about 71.7% vs ipIMR about 36.8%,p<0.001;Heart V5Gy:HT about 94.4% vs ipIMRT about 30.2%, p<0.001。);there were more volume received more higher dose in ipIMRT(Ipsilaterla lung V20Gy:HT about 13.6% vs ipIMRT about 17.7%,p<0.001;Heart V30Gy:HT about 1.7% vs ipIMRT about 5.6%,p<0.001). The NTCP was higher in HT than in ipIMRT. Three geometric parameters, the breast volume, angle and thorax width/thickness ratio, were the determining factors for evaluating the NTCP. Except, the breast volume, angle and thorax width/thickness ratio were the significant factor for evaluating the NTCP. When the thorax width/thickness ratio >1.6, the NTCP for heart will become double in ipIMRT;°the NTCP for ipsilateral lung of the angle>91°was 2.7times as great as the angle<91 in HT;the NTCP for ipsilateral lung of the breast volume<350c.c was 2.2 times greater than the breast volume>350c.c. Conclusion: Our results showed there were more volume received lower dose in HT. When the radiation oncologist judges which techniques is better to the patient, he should be think about the effect of the body characteristic and low dose carefully.