Funded by National / International Programs

Introduction

In this project we will address the problem of Beam Angle Optimisation (BAO)  in Intensity Modulated Radiation Therapy (IMRT).

(Image obtained using Software CERR)

• What is IMRT?

  • Radiation therapy consists in the treatment of cancerous tissues using radiation, having as goal the destruction of cancerous cells and the preservation of healthy tissues. The treatment plan is based on the patient CT images, where the radiation oncologist delineates the target volume and organs at risk. The medical physicist and/or the dosimetrist are then responsible for performing the plan aiming to deliver the prescribed dose to the tumor while minimizing the irradiation of the surrounding healthy organs and tissues. The achievement of optimal radiotherapy treatments is done through the optimization of all possible variables that can influence the dose distribution.With IMRT, the number of degrees of freedom to be optimized is so large that computation of mathematical algorithms is mandatory to achieve valuable solutions. The selection of appropriate radiation incidence directions may be decisive for the quality of the treatment.

• Why is this problem important?

  • In clinical practice, most of the time, beam directions continue to be manually selected or are optimized using gradient methods that are prone to converge to the nearest local minimum starting with the initial beam incidence directions.In this project we will work on computer-aided inverse planning applied to radiation therapy treatments focusing on the resolution of the beam angle optimization (BAO) problem. We aim at improving the quality of the treatments which may increase treatment outcome and quality of life while reducing treatment planning time.

• What do we propose to do?

  • We aim to develop and test new approaches for the resolution of the BAO problem, using both derivative-free optimization methods and evolutionary algorithms (EA) to tackle this highly non-convex optimization problem. See the full description for a more detailed description.

• Who are we?

  • This is an interdisciplinary project, with researchers having a solid background on computer science, optimization, medical physics and clinical practice. From the computer science and optimization side, the team has expertise in creating algorithms in multidisciplinary optimization including derivative-free algorithms and evolutionary computation. From the medical physics side, the team counts with specialized researchers, with a sound experience in treatment planning both from the research and from the clinical practice points of view. The synergies that will be possible to exploit set the grounds for a future quality research and contribute to the innovative character of our proposed work.

The development of this project will have academic impact by the development and application of derivative-free and EA to challenging real world problems. However, since this project is to be developed in straight collaboration with the Portuguese Institute of Oncology of Coimbra (IPOC), our main goal is to reflect the academic empirical achievements on the improvement of patient’s treatments.

Description

Inverse planning problems applied to radiation therapy treatments are of interest for both the academic and applied points of view. From the development and improvement of mathematical models to the design of innovative resolution algorithms capable of dealing with large scale mathematical problems, this area of research is an almost inexhaustible source of scientific challenges. From the applied point of view, inverse planning methodologies can help the daily work of radiation therapy treatment planners, increasing the quality of treatment delivered to patients. The increased capabilities of the present physical devices allow the delivery of treatments that are more effective and that have fewer side effects. Nevertheless, their increased complexity makes the planning task harder, and the trial and error procedures do not guarantee the best possible treatment. These problems are interdisciplinary by nature and require the collaboration of computer science and operations research specialists with medical physicists.

In this project we intend to focus our attention in the resolution of the BAO problem. This problem is important due to two main reasons. First, the choice of adequate directions may be decisive for the quality of the treatment. Second, changing beam directions during treatment is time consuming, and short treatments are desirable because the probability of the patient altering his position on the couch increases with the duration of the treatment. It is a challenging global non-convex optimization problem with many local minima yet to be solved satisfactorily. Not only good quality solutions have to be found, but also they have to be found within a reasonable time window (due to clinical practice requirements).

Our objective is to introduce new approaches for the resolution of the BAO problem, using direct search methods and evolutionary algorithms. We also intend to investigate the use of non-coplanar beam directions and to determine the minimum number of incidence directions to be used.

The formulation of the BAO problem as a continuous non-convex optimization instead of the traditional combinatorial optimization problem is a natural formulation since BAO problem is in fact continuous. The common choice of using a combinatorial optimization formulation problem is mainly caused by the non-use of appropriate methods to address the non-convex nonlinear formulation, namely methods that require few function evaluations, and that are suited to address problems with many local minima. Among direct search methods we intend to develop strategies based on pattern search methods tailored for the BAO problem. Pattern search methods are a suitable approach due to their structure, organized around two phases at each and every iteration, one where convergence to a local minima is assured (poll), and other (search), where flexibility is given to the method since any strategy can be applied as long as only a finite number of points is tested. This allows the insertion of previously used and tested strategies/heuristics that successfully address the BAO problem and enhance a global search by influencing the quality of the local minimizer or stationary point found by the method. Pattern search methods have the ability to avoid being trapped by the closest local minima of the starting iterate, and find a local minimum in a lowest region. Preliminary tests were conducted on the basis of retrospective treated cases of head and neck tumors. We have shown that, for head and neck cases, a beam angle set can be locally improved in a continuous manner using pattern search methods. Moreover, it was shown that high-quality coplanar beam directions can be obtained and compete with equispaced beam directions within a clinically acceptable time frame. We have to highlight, as well, the low number of function evaluations required to obtain locally optimal solutions. The number of times the function value has to be computed is of the utmost importance, particularly when the BAO problem is modeled using the optimal values of the FMO problem. The results obtained are very encouraging and reinforce our belief that pursuing this line of research can produce effective improvements on the quality of this type of oncologic treatments.

Optimization problems involving a huge search space are good candidates to be solved by an Evolutionary Algorithm. Even if we know, since the No Free Lunch (NFL) theorem, that there is no best algorithmic problem solver, that does not mean that we cannot have a good solution for a particular class of problems. In the case of the BAO problem we will need to develop and test an EA tuned for that problem. To that end, we will use a representation that takes into account that we have to deal with a continuous domain. Second, special variations operators will be tested that will incorporate knowledge about the problem. Both the representation and the operators will foster evolvability. This is important because, due to time constraints, we will need to reduce the number of generations that the EA will use to evolve a good solution. Third, the variation operators must be such as to maintain a high diversity in the population, to avoid premature convergence. Fourth, we will introduce a memory mechanism, so the algorithm can react quickly every time a similar situation to one already solved in the past appears.  It is also worth mentioning that relying on an individual representation with variable length, we can also test the ability of our algorithm to come up with a solution that minimizes the number of beams.

The far most important objective of this research is to provide means for the quality improvement of treatments delivered to patients.Summarizing, we can say that our main objective is to develop computer-aided algorithms that will improve/complement the existing commercial inverse planning software and are able to help medical physicists to build better treatment plans, with an improvement in the quality of treatments delivered to patients.

TASKS

• Beam Angle Optimization using direct search
• Beam Angle Optimization using evolutionary algorithms
• Determination of minimum number of incidence directions
• Introduction of non-coplanar directions

People

• Researchers

Joana Matos Dias has a BSc in Computers Engineering (1996), a MSc in Operations Research (2000), a MSc in Quantitative Finance (2011) and a PhD in Management Science (2006). She is an Assistant Professor at University of Coimbra, where she has been responsible for several course units like logistics, operations research, modeling in management, simulation. She is also a researcher at Inesc-Coimbra. Her main research interest is decision making models and algorithms in general, and operations research applied to health problems, combinatorial optimization, location problems in particular. She is author or co-author of two books, more than 30 papers in refereed international journals, conference proceeding and book chapters.

Personal homepage: https://www.uc.pt/feuc/joanamatosdias

Humberto Pereira Rocha is currently a Researcher at the Inesc-Coimbra Research Center. He received both his bachelors and masters degrees in Applied Mathematics from the University of Coimbra in 1998 and 2001, respectively. He completed a PhD in Computational and Applied Mathematics at Old Dominion University (ODU) and NASA Langley Research Center, both in Virginia, USA. His main areas of research are the development and analysis of numerical methods for large-scale linear/nonlinear programming, integer optimization, and derivative-free optimization. Most of his research centers on applications in physics, inverse engineering, aeronautics, and presently radiotherapy. This multidisciplinary approach leads to publications in a variety of journals and to many presentations and lectures on computational and applied mathematics and related applications in several different countries and for audiences with distinct backgrounds.

Ernesto Costa is Full Professor at the Department of Informatics Engineering of the University of Coimbra (Portugal). He got a Ph.D. in Electronic Engineering (area of Computing Science) in 1985. His main research interests are in the areas of Evolutionary Computation, Artificial Life, Complex Systems, Machine Learning, Cognition and Computational Biology. He participated in several projects, got several best paper awards. He was the recipient of the “2009 EvoStar Award for Outstanding Contributions to the Field of Evolutionary Computation”. He   organized several international scientific events and had published over 150 papers in books, journals and proceedings of conferences. He is member of the editorial board of several journals.

Anabela  Simões is Assistant Professor at the Coimbra Institute of Engineering. She is, since 1996,  member of the Centre for Informatics and Systems of the University of Coimbra (CISUC). From 1996 to 2003 she belonged to the Artificial Intelligence Group. In 2003 she became a founding member of the Evolutionary and Complex Systems Group (ECOS) of CISUC  where she is currently a Senior Researcher.She received the 5 years BSc (1995), MSc (1999) and PhD (2010) degrees in Computer Engineering from the University of Coimbra. Her research interest covers the following areas: genetic and evolutionary computation, memetic computing, swarm intelligence (particle swarm optimization and ant colony optimization), estimation of distributions algorithms, meta-heuristics and hyper-heuristics, artificial neural networks for scheduling, computational intelligence for combinatorial  and dynamic optimization problems, intelligent systems, data mining, intelligent data analysis and data integration. She is co-author, with  Ernesto Costa, of the textbook Artificial Intelligence: Foundations and Applications (in portuguese).

Brigida da Costa Ferreira is a researcher at I3N Department of Physics from Aveiro University. She graduated at the Science Faculty of Lisbon University and did her PhD at Karolinska Institutet and Stockholm University. The subject of her PhD thesis was biological optimization of breast and cervix tumours. Her postdoc was done at Aveiro University and the Medical Physics Department of the IPOCFG aiming to implement IMRT for head and neck tumours and Stereotactic IMRT for brain lesions. Presently, still within the collaboration between Aveiro University and the Medical Physics department of IPOCFG, her research project involves the development of tools to collect clinical patient data for radiobiological studies. Her work was published in international journals like Medical Physics, Radiation Oncology, Physics Medicine and Biology, Acta Oncologica, Physica Medica (awarded best paper 2006-2007), etc. Some of her main interests are: implementation of sophisticated radiation therapy techniques (IMRT, IGRT, ART, ion therapy); radiobiological optimization and evaluation of radiation therapy and evaluation of clinical outcomes.

Maria do Carmo Lopes is Head of the Medical Physics Department of the Portuguese Institut of Oncology in Coimbra (IPOCFG, E.P.E.), with 20 years experience in Medical Physics with special interest in Radiotherapy. She has been invited Associated Professor at Aveiro University (I3N, Physics Dept.) since 2008. Her PhD. was obtained in 1991, in Radiation Physics at Coimbra University. She has been deeply involved in the clinical development of new techniques in Radiotherapy, like radiosurgery, stereotactic radiotherapy and IMRT. She has coordinated many education and training activities, namely Radiation Protection Courses for different health care professionals, in the Centre of Permanent Professional Development at IPOC and she has collaborated with different universities in graduation and post-graduation programs. She has been the Coordinator of the Medical Physics Division of the Portuguese Physics Society and the National Member Officer of the European Federation of Organizations for Medical Physics (EFOMP) during the period 2005-2012. She was member of the Physics Committee of ESTRO in 2005-2011. She was the Chair of the Education and Training Committee in the International Organization for Medical Physics (IOMP) during the last term 2009-2012. She is presently member of the Scientific Committee at EFOMP and of the Education and Training Committee at IOMP. She is active in various national and international research projects, namely with the International Atomic Energy Agency (IAEA).

Tiago Ventura is a physicist at the Medical Physics Department of the Portuguese Institute of Oncology Francisco Gentil in Coimbra (IPOCFG, EPE) since 2007. He has completed his degree in Physics Engineering at University of Aveiro in 2007 and was awarded with the prize for the best graduating student of Physics Engineering of the year. His main field of interests covers the development of tools for quality assurance in radiation therapy and the implementation of new sophisticated techniques such as Radiosurgery, Intensity Modulated Radiation Therapy and Stereotactic radiotherapy. Presently is doing his PhD in Physics Engineering at University of Aveiro. His research project is in the field of clinical implementation of gantry angle optimization, evaluation of physical and biological objective functions and plan evaluation.

•  Consultants

Publications

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2015) “Does Beam Angle Optimization Really Matter for Intensity-Modulated Radiation Therapy?” Computational Science and Its Applications, O. Gervasi et al. (Eds.):, Part II, LNCS 9156, Part II, pp. 522-533 (pdf) 

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2015) “Noncoplanar beam angle optimization in IMRT treatment planning using pattern search methods” Journal of Physics: Conference Series, vol 616, 012014 (pdf)

Dias, Joana, H. Rocha, B. C. Ferreira and M. C. Lopes (2014) “Simulated Annealing applied to IMRT Beam Angle Optimization: a computational study”, Physica Medica: European Journal of Medical Physics (accepted for publication) (pdf)

Dias, Joana, Humberto Rocha, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “IMRT Beam Angle Optimization using Differential Evolution”, 2014 IEEE International Conference on Bioinformatics and Biomedicine, Workshop on Computational Intelligence for Biomedicine and Bioinformatics, pp 22-29

 Soares, Inês, Joana Dias, Humberto Rocha, Maria do Carmo Lopes, Brígida Ferreira (2014) “Predicting Xerostomia induced by IMRT treatments: a logistic regression approach”, 2014 IEEE International Conference on Bioinformatics and Biomedicine, International Workshop on Biomedical and Health Informatics, pp 72-77

Ferreira, Brígida, Leila Khouri, Maria Do Carmo Lopes, Hervê Ferreira (2014) “RESPONSE, an Electronic Health Patient Information Software for Radiation
Therapy” I. Lackovic and D. Vasic (eds.): 6th European Conference of the International Federation for Medical and Biological Engineering, IFMBE Proceedings 45, pp. 691-694, Springer International Publishing, Switzerland (pdf).

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “A Two-Stage programming approach to fluence map optimization for intensity-modulated radiation treatment planning” I. Lackovic and D. Vasic (eds.): 6th European Conference of the International Federation for Medical and Biological Engineering, IFMBE Proceedings 45, pp. 687-690, Springer International Publishing, Switzerland (pdf).

Dias, Joana, Humberto Rocha, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “IMRT Inverse Planning using Simulated Annealing” I. Lackovic and D. Vasic (eds.): 6th European Conference of the International Federation for Medical and Biological Engineering, IFMBE Proceedings 45, pp. 699-702, Springer International Publishing, Switzerland (pdf).

Dias, Joana, H. Rocha, B. C. Ferreira and M. C. Lopes (2014) “A genetic algorithm with neural network fitness function evaluation for IMRT beam angle optimization”, Central European Journal of Operations Research, 22 (3), pp 431-455 (pdf)

Dias, Joana, Humberto Rocha, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “IMRT Beam Angle Optimization Using DDS with a Cross-Validation Approach for Configuration Selection” Computational Science and Its Applications, B. Murgante et al. (Eds.): ICCSA 2014, Part II, LNCS 8580, pp. 1-16

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “IMRT Beam Angle Optimization Using Non-descent Pattern Search Methods” Computational Science and Its Applications, B. Murgante et al. (Eds.): ICCSA 2014, Part II, LNCS 8580, pp. 17–31

Rocha, Humberto, Ana Maria A.C. Rocha, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “IMRT Beam Angle Optimization Using Electromagnetism-Like Algorithm” Computational Science and Its Applications, B. Murgante et al. (Eds.): ICCSA 2014, Part II, LNCS 8580, pp. 278–289

Dias, Joana, Humberto Rocha, Brígida Costa Ferreira, Maria do Carmo Lopes (2013) “IMRT Beam Angle Optimization Using Dynamically Dimensioned Search”, I. Lacković et al. (eds.), The International Conference on Health Informatics, IFMBE Proceedings 42, pp 1-4 (pdf)

Dias, Joana, Rupa Jaganathan, Sanja Petrovic (2013) “Determining the number of beams in 3D conformal radiotherapy: a classification approach”, HCIST 2013 – International Conference on Health and Social Care Information Systems and Technologies, Procedia Technology, 9, pp 958-967 (pdf)

H. Rocha, J. Dias, B. C. Ferreira and M. C. Lopes (2013) “Selection of intensity modulated radiation therapy treatment beam directions using radial basis functions within a pattern search methods framework”, Journal of Global Optimization,  vol. 57, pp 1065‑1089 (pdf)

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2013) “On the Global Optimization of the Beam Angle Optimization Problem in Intensity-Modulated Radiation Therapy” L.M. Roa Romero (ed.), XIII Mediterranean Conference on Medical and Biological Engineering and Computing 2013, IFMBE Proceedings 41, 1374-1377 (pdf)

Rocha, Humberto, J. Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2013) “On the Use of A Priori Knowledge in Pattern Search Methods: Application to Beam Angle Optimization for Intensity-Modulated Radiation Therapy” Computational Science and Its Applications (ICCSA 2013), Murgante, B., Misra, S., Carlini, M., Torre, C., Nguyen, H.-Q., Taniar, D., Apduhan, B.O., Gervasi, O. (Eds.), LNCS, vol. 7971, pp 279-292 (pdf)

H. Rocha, J. Dias, B. C. Ferreira and M. C. Lopes (2013) “Pattern search methods framework for beam angle optimization in radiotherapy design”, Applied Mathematics and Computation, vol. 219 (23), pp 10853-10865 (pdf)

H. Rocha, J. Dias, B. C. Ferreira and M. C. Lopes (2013) “Beam angle optimization for intensity-modulated radiation therapy using a guided pattern search method”, Physics in Medicine and Biology, vol. 58, pp 2939-2953 (pdf)

H. Rocha, J. Dias, B. C. Ferreira and M. C. Lopes (2013) “Otimização do planeamento inverso de tratamentos em radioterapia”, Investigação Operacional em Ação: Casos de Aplicação  (in Portuguese, accepted for publication)

H. Rocha, J. Dias, B. C. Ferreira, and M. C. Lopes (2012) “Incorporating Radial Basis Functions in Pattern Search Methods: Application to Beam Angle Optimization in Radiotherapy Treatment Planning”, B. Murgante et al. (Eds.): ICCSA 2012, Part III, LNCS 7335, pp. 1–16

H. Rocha,  Joana Dias, B. C. Ferreira, and M. C. Lopes (2012) “Discretization of optimal beamlet intensities in IMRT: a binary integer programming approach”, Mathematical and Computer Modelling, vol. 55, pp 1969-1980 (pdf)

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2012) “Beam Angle Optimization in IMRT using Pattern Search Methods: Initial Mesh-Size Considerations”, ICORES proceedings, 1st International Conference on Operations Research and Enterprise Systems, pp 355-360 (pdf).

H. Rocha, Joana Dias, B. C. Ferreira,  M. C. Lopes (2012) “Combinatorial optimization for an improved transition from fluence optimization to fluence delivery in IMRT treatment planning”, Optimization, vol 61, n. 8, pp 969-987 (pdf).

H. Rocha,Joana Dias, B. C. Ferreira, and M. C. Lopes (2011), “Influence of Sampling in Radiation Therapy Treatment Design”. B. Murgante et al. (Eds.): ICCSA 2011, Part III, Lecture Notes in Computer Science 6784, pp. 215–230, Springer-Verlag, Berlin, Heidelberg (pdf)

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2011) “On the transition from fluence map optimization to fluence map delivery in intensity modulated radiation therapy treatment planning” Proceedings of the VII ALIO–EURO, Workshop on Applied Combinatorial Optimization, Porto, Portugal, May 4–6, 2011, pp 173-176

Research Reports

Rocha, Humberto, Joana Dias, Brígida C. Ferreira, Maria Carmo Lopes (2012) “Beam angle optimization in intensity-modulated radiation therapy using radial basis functions within the pattern search methods framework” , Research Report n.1-2012, Inesc-Coimbra (pdf)

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2011) “From fluence map optimization to fluence map delivery:the role of combinatorial optimization” , Research Report n. 5-2011, Inesc-Coimbra (pdf)

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2010) “Towards efficient transition from optimized to delivery fluence maps in inverse planning of radiotherapy desing”,  Research Report n. 7-2010, Inesc-Coimbra (pdf)

 Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2010) “Direct search applied to beam angle optimization in radiotherapy design”,  Research Report n. 6-2010, Inesc-Coimbra (pdf)

Rocha, Humberto, Joana Dias (2009) “On the Optimization of Radiation Therapy Planning”,  Research Report n. 15-2009, Inesc-Coimbra. (pdf)

Conferences

Dias, Joana, Humberto Rocha, Tiago Ventura, Brígida Costa Ferreira, Maria do Carmo Lopes (2015) “Automated Iterative Non-Linear Optimization for IMRT Fluence Map Optimization”, 27th European Conference on Operational Research, Glasgow, United Kingdom, University of Strathclyde, 12-15 July 2015

Dias, Joana, Humberto Rocha, Tiago Ventura, Brígida Costa Ferreira, Maria do Carmo Lopes (2015) “Fluence Map Non-Linear Continuous Optimization for IMRT Treatment Planning”, 13th EUROPT Workshop on Advances in Continuous Optimization, Edinburgh, United Kingdom, 8-10 July 2015

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2015) “Does Beam Angle Optimization Really Matter for Intensity-Modulated Radiation Therapy?” Computational Science and Its Applications, ICCSA 2015, University of Calgary, Banff, Canada – June 22-June 25

Rocha, H., Joana Dias, B. C. Ferreira, M. C. Lopes (2015) “Noncoplanar beam angle optimization in IMRT treatment planning using pattern search methods”, Euro Mini‑Conference on Improving Healthcare: new challenges, new approaches, 30 March to 1 April 2015, Coimbra, Portugal

Soares, Inês, Joana Dias, H. Rocha, L. Khouri, M. C. Lopes, B. Ferreira (2015) “Predicting Xerostomia after IMRT treatments: A data mining approach” Euro Mini‑Conference on Improving Healthcare: new challenges, new approaches, 30 March to 1 April 2015, Coimbra, Portugal

Dias, Joana, Humberto Rocha, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “IMRT Beam Angle Optimization using Differential Evolution”, 2014 IEEE International Conference on Bioinformatics and Biomedicine, Workshop on Computational Intelligence for Biomedicine and Bioinformatics, Belfast 2-5 November 2014

Soares, Inês, Joana Dias, Humberto Rocha, Maria do Carmo Lopes, Brígida Ferreira (2014) “Predicting Xerostomia induced by IMRT treatments: a logistic regression approach”, 2014 IEEE International Conference on Bioinformatics and Biomedicine, International Workshop on Biomedical and Health Informatics, Belfast 2-5 November 2014

Dias, Joana, H. Rocha, B. C. Ferreira, M. C. Lopes (2014) “ Simulated annealing applied to IMRT beam angle optimization: A computational study”, 8th European Conference on Medical Physics, Athens, Greece, September 2014.

Rocha, H., Joana Dias, B. C. Ferreira, M. C. Lopes (2014) “Noncoplanar beam angle optimization in IMRT treatment planning using derivative-free algorithms”, 8th European Conference on Medical Physics, Athens, Greece, September 2014 (E-Poster – Best paper presentation award).

Rocha, H., Joana Dias, B. C. Ferreira, M. C. Lopes (2014) “A two-stage programming approach to fluence map optimization for intensity- modulated radiation therapy treatment planning”, 6th European Conference of the International Federation for Medical and Biological Engineering (MBEC 2014), Dubrovnik, Croatia, September 2014.

Dias, Joana, H. Rocha, B. C. Ferreira, M. C. Lopes (2014) “IMRT Inverse Planning using Simulated Annealing”, 6th European Conference of the International Federation for Medical and Biological Engineering (MBEC 2014), Dubrovnik, Croatia, September 2014.

Dias, Joana, H. Rocha, B. C. Ferreira, M. C. Lopes (2014) “A Simulated Annealing Approach Using a DDS-based neighborhood for IMRT Beam Angle Optimization” 20th Conference of the International Federation of Operational Research Societies IFORS 2014, Barcelona, Spain, 13-18 July 2014

Dias, Joana, Humberto Rocha, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “IMRT Beam Angle Optimization Using DDS with a Cross-Validation Approach for Configuration Selection” Computational Science and Its Applications (ICCSA 2014), Guimarães, Portugal, 30 June – 3 July 2014

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “IMRT Beam Angle Optimization Using Non-descent Pattern Search Methods” Computational Science and Its Applications (ICCSA 2014), Guimarães, Portugal, 30 June – 3 July 2014 (presented by Humberto Rocha)

Rocha, Humberto, Ana Maria A.C. Rocha, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “IMRT Beam Angle Optimization Using Electromagnetism-Like Algorithm” Computational Science and Its Applications (ICCSA 2014), Guimarães, Portugal, 30 June – 3 July 2014 (presented by Humberto Rocha)

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2014) “IMRT beam angle optimization using a physics-guided derivative-free algorithm”, XXX EURO mini Conference “Optimization in the Natural Sciences”, February 5–9, Aveiro, Portugal (presented by Humberto Rocha)

Dias, Joana, Humberto Rocha, Brígida Costa Ferreira, Maria do Carmo Lopes (2013) “IMRT Beam Angle Optimization Using Dynamically Dimensioned Search”, IFMBE International Conference on Health Informatics, 7-9 November 2013, Vilamoura, Portugal

Dias, Joana, Rupa Jaganathan, Sanja Petrovic (2013) “Determining the number of beams in 3D conformal radiotherapy: a classification approach”, HCIST 2013 – International Conference on Health and Social Care Information Systems and Technologies, 23-25 October 2013, Lisbon, Portugal

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2013) “On the Global Optimization of the Beam Angle Optimization Problem in Intensity-Modulated Radiation Therapy” XIII Mediterranean Conference on Medical and Biological Engineering and Computing 2013, 25-28 September Sevilla, Spain

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2013) “On the Use of A Priori Knowledge in Pattern Search Methods: Application to Beam Angle Optimization for Intensity-Modulated Radiation Therapy” The 13th International Conference on Computational Science and Its Applications (ICCSA 2013), June 24-27, Vietnam

Humberto Rocha, Joana Dias, Brígida Ferreira, Maria do Carmo Lopes (2013) “Otimização angular no planeamento inverso de tratamentos de IMRT: uma abordagem usando algoritmos sem derivadas”, IO 2013, XVI Congresso da Associação Portuguesa de Investigação Operacional, 3-5 Junho 2013, Bragança, Portugal

H. Rocha, J. M. Dias, B. C. Ferreira, and M. C. Lopes, “Beam angle optimization using derivative-free algorithms incorporating beam’s-eye-view dose metrics”. Radiotherapy & Oncology 106, Supp. 2, pp. S226, March 2013. Poster discussion (M. C. Lopes) at the 2nd ESTRO Forum, Geneva, Switzerland, April 2013. (abstract pdf)

Dias, Joana, H. Rocha (2012) “A two-stage genetic algorithm for IMRT beam angle optimization”, International Symposium on Combinatorial Optimization 2012, 17–19 September 2012,University of Oxford, UK

Dias, Joana, H. Rocha (2012) “A genetic algorithm with neural network fitness function evaluation for IMRT beam angle optimization”, The 2012 Mini EURO Conference on Computational Biology, Bioinformatics and Medicine, University of Nottingham, 13‑15 September 2012

Dias, Joana, H. Rocha (2012) “Using neural networks to map beam angles into intensity objective function values in IMRT optimization problems”, 25th European Conference on Operational Research (EURO2012), 8-11 July, Vilnius

H. Rocha, J. Dias, B. C. Ferreira, and M. C. Lopes (2012) “Incorporating Radial Basis Functions in Pattern Search Methods: Application to Beam Angle Optimization in Radiotherapy Treatment Planning”, The 12th International Conference on Computational Science and Its Applications (ICCSA 2012), June 18-21, Salvador de Bahia, Brazil

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2012) “Beam Angle Optimization in IMRT using Pattern Search Methods: Initial Mesh-Size Considerations”, 1st International Conference on Operations Research and Enterprise Systems, 4-6 Fevereiro 2012, Vilamoura, Algarve

H. Rocha, J. Dias, B. C. Ferreira, and M. C. Lopes (2011) “Influence of Sampling in Radiation Therapy Treatment Design”, The 11th International Conference on Computational Science and Its Applications (ICCSA 2011), June 20-23, 2011, , Santander, Spain

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2011) “On the transition from fluence map optimization to fluence map delivery in intensity modulated radiation therapy treatment planning” VII ALIO–EURO, Workshop on Applied Combinatorial Optimization, Porto, Portugal, May 4–6, 2011

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2011) “Beam Angle Optimization using Derivative-Free Algorithms” 11th Biennial on Physics & Radiation Technology For Clinical Radiotherapy, 8-12 May 2011 – London, UK

Rocha, Humberto, Joana Dias, Brígida Costa Ferreira, Maria do Carmo Lopes (2010) “Sampling issues for intensity modulated radiation therapy (IMRT) treatment planning”, 24rd European Conference on Operational Research, 10-14 de July, Lisbon, Portugal

Euro Mini Conference 2015

Improving Healthcare: new challenges, new approaches

Recent advances in medicine allow us to live longer and healthier lives. These advances have been made possible through the joint contribution of very different scientific fields. Healthcare is nowadays better understood as a multidisciplinary field, with increasing number of challenges that can be better tackled by joint collaboration of researchers with different scientific backgrounds.

The challenges that Healthcare is facing have not only to do with the ability of providing better services to all (treatments, preventive medicine, better diagnosis tools), with an increased focus on improved personalized treatment options, but also with the need to tackle an increased pressure felt by Healthcare systems: increased number of patients, some of them requiring expensive treatments, with a consequent increase in the workload for health institutions that most of the times have to deal with important budget restrictions.

The Conference will provide a forum in which researchers coming from different scientific disciplines can discuss and share their experience regarding methodological approaches to tackle different Healthcare challenges. Contributions from operational research, industrial engineering, medicine, medical physics, management, computational biology, bioinformatics, health economics among others are welcomed.

Please visit the conference website.

Contacts

If you want more information about our project, or if you think that you could collaborate with us, please feel free to contact us:

Joana Dias
INESC Coimbra – Instituto de Engenharia de Sistemas e Computadores de Coimbra

Rua Antero de Quental, Nº199 
3000 – 033 Coimbra 
Portugal

Email: joana@fe.uc.pt
tel: +351239790571