Download or read book Optimization of Cancer Radiotherapy written by Bhudatt R. Paliwal and published by American Institute of Physics. This book was released on 1985 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optimization of Human Cancer Radiotherapy written by G.W. Swan and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mathematical models in this book are concerned with a variety of approaches to the manner in which the clinical radiologic treatment of human neoplasms can be improved. These improvements comprise ways of delivering radiation to the malignan cies so as to create considerable damage to tumor cells while sparing neighboring normal tissues. There is no unique way of dealing with these improvements. Accord ingly, in this book a number of different presentations are given. Each presentation has as its goal some aspect of the improvement, or optimization, of radiotherapy. This book is a collection of current ideas concerned with the optimization of human cancer radiotherapy. It is hoped that readers will build on this collection and develop superior approaches for the understanding of the ways to improve therapy. The author owes a special debt of thanks to Kathy Prindle who breezed through the typing of this book with considerable dexterity. TABLE OF CONTENTS Chapter GENERAL INTRODUCTION 1. 1 Introduction 1 1. 2 History of Cancer and its Treatment by Radiotherapy 8 1. 3 Some Mathematical Models of Tumor Growth 12 1. 4 Spatial Distribution of the Radiation Dose 20 Chapter 2 SURVIVAL CURVES FROM STATISTICAL MODELS 24 2. 1 Introduction 24 2. 2 The Target Model 26 2. 3 Single-hit-to-kill Model 27 2. 4 Multitarget, Single-hit Survival 29 2. 5 Multitarget, Multihit Survival 31 2. 6 Single-target, Multihit Survival 31 2.
Download or read book Radiation Therapy Physics written by Alfred R. Smith and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to provide a uniquely comprehensive source of information on the entire field of radiation therapy physics. The very significant advances in imaging, computational, and accelerator technologies receive full consideration, as do such topics as the dosimetry of radiolabeled antibodies and dose calculation models. The scope of the book and the expertise of the authors make it essential reading for interested physicians and physicists and for radiation dosimetrists.
Download or read book Biomathematical Problems in Optimization of Cancer Radiotherapy written by A.Y. Yakovlev and published by CRC Press. This book was released on 2020-11-26 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomathematical Problems in Optimization of Cancer Radiotherapy provides insight into the role of cell population heterogeneity in the optimal control of fractionated irradiation of tumors. The book emphasizes the mathematical modeling aspect of the problem and presents the state of the art in the stochastic description of irradiated cell survival. Some of the results are of general theoretical interest and can be applied to other areas of optimal control methodology. Detailed explanations of all mathematical statements are provided throughout the text. The book is excellent for biomathematicians, radiotherapists, oncologists, health physicists, and other researchers and students interested in the topic.
Download or read book Optimization of Human Cancer Radiotherapy written by G W Swan and published by . This book was released on 1981-10-01 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling Radiotherapy Side Effects written by Tiziana Rancati and published by CRC Press. This book was released on 2019-06-11 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: The treatment of a patient with radiation therapy is planned to find the optimal way to treat a tumour while minimizing the dose received by the surrounding normal tissues. In order to better exploit the possibilities of this process, the availability of accurate and quantitative knowledge of the peculiar responses of the different tissues is of paramount importance. This book provides an invaluable tutorial for radiation oncologists, medical physicists, and dosimetrists involved in the planning optimization phase of treatment. It presents a practical, accessible, and comprehensive summary of the field’s current research and knowledge regarding the response of normal tissues to radiation. This is the first comprehensive attempt to do so since the publication of the QUANTEC guidelines in 2010. Features: Addresses the lack of systemization in the field, providing educational materials on predictive models, including methods, tools, and the evaluation of uncertainties Collects the combined effects of features, other than dose, in predicting the risk of toxicity in radiation therapy Edited by two leading experts in the field
Download or read book Optimization Formulations and Algorithms for Cancer Therapy written by Kelsey Lynn Maass and published by . This book was released on 2021 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: Underlying all cancer therapy protocols are the competing objectives of maximizing tumor control and minimizing normal-tissue complications. As such, we can formulate many aspects of the cancer treatment planning workflow as optimization problems, enabling the development of mathematically rigorous treatment planning methods. In this dissertation, we present three novel optimization approaches to problems in cancer treatment planning: 1) a Markov decision process approach for optimizing multi-modality cancer therapy that balances the trade-off between tumor control and normal-tissue complication, 2) a nonconvex relaxation for the fluence map optimization problem for intensity-modulated radiation therapy that is well adapted to handle nonconvex dose-volume constraints, and 3) a hyperparameter optimization formulation for stereotactic body radiation therapy that has the potential to improve treatment plan quality and reduce the time needed to create a clinically acceptable treatment plan. We demonstrate the feasibility and potential benefit of each approach through numerical examples using synthetic and clinical cancer patient datasets. All project data and code are made openly available on GitHub.
Download or read book Biologically Optimized Radiation Therapy written by Anders Brahme and published by World Scientific Publishing Company. This book was released on 2014-03-21 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation therapy has developed and advanced dramatically in the last few decades. However, very little has been published or done in the area of biologically optimized treatment planning. Development of Biologically Optimized Radiation Therapy aims to fill and close an important gap in the literature with a well-focused and in-depth content.The book covers the biological, physical and clinical background of advanced biologically based radiation therapy optimization with focus on modern radiation therapy modalities such as electron, photon and light ion therapy. Highly recommended for its strong interdisciplinary profile, the book contains a meritorious compilation of previously unpublished materials in many areas of modern science. Undergraduates, researchers and practitioners such as oncologists, medical physicists and radiation biologists alike should find the book immensely informative and comprehensively thorough.
Download or read book Designing Radiation Therapy for Cancer written by Witold Paluszyński and published by . This book was released on 1990 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Treatment Planning of High Dose Rate Brachytherapy Mathematical Modelling and Optimization written by Björn Morén and published by Linköping University Electronic Press. This book was released on 2021-01-12 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cancer is a widespread class of diseases that each year affects millions of people. It is mostly treated with chemotherapy, surgery, radiation therapy, or combinations thereof. High doserate (HDR) brachytherapy (BT) is one modality of radiation therapy, which is used to treat for example prostate cancer and gynecologic cancer. In BT, catheters (i.e., hollow needles) or applicators are used to place a single, small, but highly radioactive source of ionizing radiation close to or within a tumour, at dwell positions. An emerging technique for HDR BT treatment is intensity modulated brachytherapy (IMBT), in which static or dynamic shields are used to further shape the dose distribution, by hindering the radiation in certain directions. The topic of this thesis is the application of mathematical optimization to model and solve the treatment planning problem. The treatment planning includes decisions on catheter placement, that is, how many catheters to use and where to place them, as well as decisions for dwell times. Our focus is on the latter decisions. The primary treatment goals are to give the tumour a sufficiently high radiation dose while limiting the dose to the surrounding healthy organs, to avoid severe side effects. Because these aims are typically in conflict, optimization models of the treatment planning problem are inherently multiobjective. Compared to manual treatment planning, there are several advantages of using mathematical optimization for treatment planning. First, the optimization of treatment plans requires less time, compared to the time-consuming manual planning. Secondly, treatment plan quality can be improved by using optimization models and algorithms. Finally, with the use of sophisticated optimization models and algorithms the requirements of experience and skill level for the planners are lower. The use of optimization for treatment planning of IMBT is especially important because the degrees of freedom are too many for manual planning. The contributions of this thesis include the study of properties of treatment planning models, suggestions for extensions and improvements of proposed models, and the development of new optimization models that take clinically relevant, but uncustomary aspects, into account in the treatment planning. A common theme is the modelling of constraints on dosimetric indices, each of which is a restriction on the portion of a volume that receives at least a specified dose, or on the lowest dose that is received by a portion of a volume. Modelling dosimetric indices explicitly yields mixed-integer programs which are computationally demanding to solve. We have therefore investigated approximations of dosimetric indices, for example using smooth non-linear functions or convex functions. Contributions of this thesis are also a literature review of proposed treatment planning models for HDR BT, including mathematical analyses and comparisons of models, and a study of treatment planning for IMBT, which shows how robust optimization can be used to mitigate the risks from rotational errors in the shield placement. Cancer är en grupp av sjukdomar som varje år drabbar miljontals människor. De vanligaste behandlingsformerna är cellgifter, kirurgi, strålbehandling eller en kombination av dessa. I denna avhandling studeras högdosrat brachyterapi (HDR BT), vilket är en form av strålbehandling som till exempel används vid behandling av prostatacancer och gynekologisk cancer. Vid brachyterapibehandling används ihåliga nålar eller applikatorer för att placera en millimeterstor strålkälla antingen inuti eller intill en tumör. I varje nål finns det ett antal så kallade dröjpositioner där strålkällan kan stanna en viss tid för att bestråla den omkringliggande vävnaden, i alla riktningar. Genom att välja lämpliga tider för dröjpositionerna kan dosfördelningen formas efter patientens anatomi. Utöver HDR BT studeras också den nya tekniken intensitetsmodulerad brachyterapi (IMBT) vilket är en variation på HDR BT där skärmning används för att minska strålningen i vissa riktningar vilket gör det möjligt att forma dosfördelningen bättre. Planeringen av en behandling med HDR BT omfattar hur många nålar som ska användas, var de ska placeras samt hur länge strålkällan ska stanna i de olika dröjpositionerna. För HDR BT kan dessa vara flera hundra stycken medan det för IMBT snarare handlar om tusentals möjliga kombinationer av dröjpositioner och inställningar av skärmarna. Planeringen resulterar i en dosplan som beskriver hur hög stråldos som tumören och intilliggande frisk vävnad och riskorgan utsätts för. Dosplaneringen kan formuleras som ett matematiskt optimeringsproblem vilket är ämnet för avhandlingen. De övergripande målsättningarna för behandlingen är att ge en tillräckligt hög stråldos till tumören, för att döda alla cancerceller, samt att undvika att bestråla riskorgan eftersom det kan ge allvarliga biverkningar. Då alla målsättningarna inte samtidigt kan uppnås fullt ut så fås optimeringsproblem där flera målsättningar behöver prioriteras mot varandra. Utöver att dosplanen uppfyller kliniska behandlingsriktlinjer så är också tidsaspekten av planeringen viktig eftersom det är vanligt att den görs medan patienten är bedövad eller sövd. Vid utvärdering av en dosplan används dos-volymmått. För en tumör anger ett dosvolymmått hur stor andel av tumören som får en stråldos som är högre än en specificerad nivå. Dos-volymmått utgör en viktig del av målen för dosplaner som tas upp i kliniska behandlingsriktlinjer och ett exempel på ett sådant mål vid behandling av prostatacancer är att 95% av prostatans volym ska få en stråldos som är minst den föreskrivna dosen. Dos-volymmått utläses ur de kliniskt betydelsefulla dos-volym histogrammen som för varje stråldosnivå anger motsvarande volym som erhåller den dosen. En fördel med att använda matematisk optimering för dosplanering är att det kan spara tid jämfört med manuell planering. Med väl utvecklade modeller så finns det också möjlighet att skapa bättre dosplaner, till exempel genom att riskorganen nås av en lägre dos men med bibehållen dos till tumören. Vidare så finns det även fördelar med en process som inte är lika personberoende och som inte kräver erfarenhet i lika stor utsträckning som manuell dosplanering i dagsläget gör. Vid IMBT är det dessutom så många frihetsgrader att manuell planering i stort sett blir omöjligt. I avhandlingen ligger fokus på hur dos-volymmått kan användas och modelleras explicit i optimeringsmodeller, så kallade dos-volymmodeller. Detta omfattar såväl analys av egenskaper hos befintliga modeller, utvidgningar av tidigare använda modeller samt utveckling av nya optimeringsmodeller. Eftersom dos-volymmodeller modelleras som heltalsproblem, vilka är beräkningskrävande att lösa, så är det också viktigt att utveckla algoritmer som kan lösa dem tillräckligt snabbt för klinisk användning. Ett annat mål för modellutvecklingen är att kunna ta hänsyn till fler kriterier som är kliniskt relevanta men som inte ingår i dos-volymmodeller. En sådan kategori av mått är hur dosen är fördelad rumsligt, exempelvis att volymen av sammanhängande områden som får en alldeles för hög dos ska vara liten. Sådana områden går dock inte att undvika helt eftersom det är typiskt för dosplaner för brachyterapi att stråldosen fördelar sig ojämnt, med väldigt höga doser till små volymer precis intill strålkällorna. Vidare studeras hur små fel i inställningarna av skärmningen i IMBT påverkar dosplanens kvalitet och de olika utvärderingsmått som används kliniskt. Robust optimering har använts för att säkerställa att en dosplan tas fram som är robust sett till dessa möjliga fel i hur skärmningen är placerad. Slutligen ges en omfattande översikt över optimeringsmodeller för dosplanering av HDR BT och speciellt hur optimeringsmodellerna hanterar de motstridiga målsättningarna.
Download or read book Radiation Therapy Optimization Under Uncertainty for Lung Cancer written by Laleh Kardar and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Radiation therapy is a complex process where a given target volume receives a given dose of radiation divided over one or multiple treatments. Every step in this process can introduce some types of uncertainties into the problem which may compromise the quality of the treatment. Typically, a volume larger than the actual tumor is irradiated to make the treatment more robust against these uncertainties. This comes at the cost of normal tissue irradiation and an increased risk of toxicity. In this dissertation, we investigate approaches to managing uncertainties in radiation therapy treatments for lung cancer patients. In the first part of the dissertation, we focus on the process of designing a treatment plan which involves selecting appropriate beam angles and deciding the right amount of radiation dose to the tumor cells, while sparing the normal tissue surrounding the tumor. Selecting the optimal set of treatment beam angles, called beam angle optimization (BAO), involves a very large-scale combinatorial optimization problem with many local minima. In order to identify an efficient approach to obtain high quality beam angles, we first examine the strengths and weaknesses of some existing BAO optimization methods including both global and local search algorithms. We then propose a hybrid framework to overcome some of the weaknesses observed in these methods. Next, we perform an in-depth study into the impact of interplay effect, which results from relative motion of the tumor and proton beam, on the dose distribution in the patient with lung cancer. The dynamic dose distribution, that provides an estimation of delivered dose under the influence of interplay effect, is calculated by simulating the machine delivery processes on the moving patient described by 4D computed tomography (4DCT) during the dose delivery process by linking timestamps of each on/off switch of proton spots, spills, energies, and fields to patient respiratory cycles. We introduce a clinically applicable metric for clinicians to use for determining the magnitude of the uncertainties caused by interplay effects. We then explore the techniques of fractionation and iso-layered re-scanning for mitigating these interplay effects. In the last part of the dissertation, we develop a robust adaptive optimization framework for intensity modulated radiation therapy (IMRT) for lung cancer, where temporal variation of tumor volume and its associated uncertainties throughout the course of the treatment are accounted for to re-optimize the treatment plan for the following sessions. This framework gives an insight into the trade-off between sparing the healthy tissues and ensuring that the tumor receives a sufficient dose. With this trade-off in mind, we demonstrate that our robust adaptive solution outperforms a non-adaptive solution and a nominal (no uncertainty) solution on a clinical case.
Download or read book Advances in treatment planning optimization and delivery for radiotherapy of breast cancer written by Nisha Ohri and published by Frontiers Media SA. This book was released on 2024-01-19 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling Radiotherapy Side Effects written by Tiziana Rancati and published by CRC Press. This book was released on 2019 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: The treatment of a patient with radiation therapy is planned to find the optimal way to treat a tumour while minimizing the dose received by the surrounding normal tissues. In order to better exploit the possibilities of this process, the availability of accurate and quantitative knowledge of the peculiar responses of the different tissues is of paramount importance. This book provides an invaluable tutorial for radiation oncologists, medical physicists, and dosimetrists involved in the planning optimization phase of treatment. It presents a practical, accessible, and comprehensive summary of the field's current research and knowledge regarding the response of normal tissues to radiation. This is the first comprehensive attempt to do so since the publication of the QUANTEC guidelines in 2010. Features: Addresses the lack of systemization in the field, providing educational materials on predictive models, including methods, tools, and the evaluation of uncertainties Collects the combined effects of features, other than dose, in predicting the risk of toxicity in radiation therapy Edited by two leading experts in the field
Download or read book Cancer Treatment Optimization written by Kyungduck Cha and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation investigates optimization approaches applied to radiation therapy in cancer treatment. Since cancerous cells are surrounded by critical organs and normal tissues, there is conflicting objectives in the treatment design of providing sufficient radiation dose to tumor region, while avoiding normal healthy cells. In general, the goal of radiation therapy is to conform the spatial distribution of the prescribed dose to the tumor volume while minimizing the dose to the surrounding normal structures. A recent advanced technology, using multi-leaf collimator integrated into linear accelerator, provides much better opportunities to achieve this goal: the radiotherapy based on non-uniform radiation beams intensities is called Intensity-Modulated Radiation Therapy. My dissertation research offers a quadratic mixed integer programming approach to determine optimal beam orientations and beamlets intensity simultaneously. The problems generated from real patient cases are large-scale dense instances due to the physics of dose contributions from beamlets to volume elements. The research highlights computational techniques to improve solution times for these intractable instances. Furthermore, results from this research will provide plans that are clinically acceptable and superior in plan quality, thus directly improve the curity rate and lower the normal tissue complication for cancer patients.
Download or read book Optimization Approaches for Planning External Beam Radiotherapy written by Halil Ozan Gozbasi and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: External beam radiotherapy is delivered from outside the body aimed at cancer cells to damage their DNA making them unable to divide and reproduce. The beams travel through the body and may damage nearby healthy tissues unless carefullyplanned. Therefore, the goal of treatment plan optimization is to find the best system configuration to deliver sufficient dose to target structures while avoiding damage to healthy tissues. This thesis investigates optimization approaches for two external beam radiation therapy techniques: Intensity-Modulated Radiation Therapy (IMRT) and Volumetric-Modulated Arc Therapy (VMAT). We develop an automated treatment planning technology for IMRT which generates several high-quality treatment plans satisfying the provided requirements in a single invocation and without human guidance. Our approach is based on an existing linear programming-based fluence map optimization model that approximates dose-volume requirements using conditional value-at-risk (C-VaR) constraints. We show how the parameters of the C-VaR constraints can be used to control various metrics of treatment plan quality. A novel bi-criteria scoring based beam selection algorithm is developed which finds the best beam configuration at least ten times faster for real-life brain, prostate, and head and neck cases as compared to an exact mixed integer programming model. Patient anatomy changes due to breathing during the treatment of lung cancer need to be considered in treatment planning. To date, a single phase of the breathing cycle is typically selected for treatment and radiation is shut-off in other phases. We investigate optimization technology that finds optimal fluence maps for each phase of the breathing cycle by considering the overall dose delivered to a patient using image registration algorithms to track target structures and organs at risk. Because the optimization exploits the opportunities provided in each phase, better treatment plans are obtained. The improvements are shown on a real-life lung case. VMAT is a recent radiation treatment technology which has the potential to provide treatments in less time compared to other delivery techniques. This enhances patient comfort and allows for the treatment of more patients. We build a large-scale mixed-integer programming model for VMAT treatment plan optimization. The solution of this model is computationally prohibitive. Therefore, we develop an iterative MIP-based heuristic algorithm which solves the model multiple times on a reduced set of decision variables. We introduce valid inequalities that decrease solution times, and, more importantly, that identify higher quality integer solutions within specified time limits. Computational studies on a spinal tumor and a prostate tumor case produce clinically acceptable results.
Download or read book New Technologies in Radiation Oncology written by Wolfgang C. Schlegel and published by Springer Science & Business Media. This book was released on 2006-01-27 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: - Summarizes the state of the art in the most relevant areas of medical physics and engineering applied to radiation oncology - Covers all relevant areas of the subject in detail, including 3D imaging and image processing, 3D treatment planning, modern treatment techniques, patient positioning, and aspects of verification and quality assurance - Conveys information in a readily understandable way that will appeal to professionals and students with a medical background as well as to newcomers to radiation oncology from the field of physics
Download or read book Optimization of Breast Cancer Treatment by Dynamic Intensity Modulated Electron Radiotherapy written by and published by . This book was released on 2004 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since electron arc dose calculations using Monte Carlo are quite time-consuming, we have investigated "gross optimization" techniques that will allow determination of a set of starting parameters that can converge to final values within a few iterations. This will allow us to determine the final optimized leaf settings for each arc segment within a reasonable time. Included in this "gross optimization" will be use of precalculated fluence maps reflective of the treatment head geometry, so that the initial parameter set can be determined using Monte Carlo calculations only within the individual patient anatomy. These techniques will make determination of the final leaf settings very straightforward. Additionally, beam data sets have been verified for the clinical range of field sizes and energies. Lastly, we are working with Varian Medical Systems to determine a transition path from our one-of-a-kind electron arc configuration into a supportable system that can be readily available to the general radiotherapy community.
