title: Interactive multiobjective optimization for anatomy-based three-dimensional HDR brachytherapy.
abstract: In this paper, we present an anatomy-based three-dimensional dose optimization approach for HDR brachytherapy using interactive multiobjective optimization (IMOO). In brachytherapy, the goals are to irradiate a tumor without causing damage to healthy tissue. These goals are often conflicting, i.e. when one target is optimized the other will suffer, and the solution is a compromise between them. IMOO is capable of handling multiple and strongly conflicting objectives in a convenient way. With the IMOO approach, a treatment planner's knowledge is used to direct the optimization process. Thus, the weaknesses of widely used optimization techniques (e.g. defining weights, computational burden and trial-and-error planning) can be avoided, planning times can be shortened and the number of solutions to be calculated is small. Further, plan quality can be improved by finding advantageous trade-offs between the solutions. In addition, our approach offers an easy way to navigate among the obtained Pareto optimal solutions (i.e. different treatment plans). When considering a simulation model of clinical 3D HDR brachytherapy, the number of variables is significantly smaller compared to IMRT, for example. Thus, when solving the model, the CPU time is relatively short. This makes it possible to exploit IMOO to solve a 3D HDR brachytherapy optimization problem. To demonstrate the advantages of IMOO, two clinical examples of optimizing a gynecologic cervix cancer treatment plan are presented.
authors.affiliation: Department of Physics and Mathematics, University of Eastern Finland, PO Box 1627, FI-70211 Kuopio, Finland. henrimatias.ruotsalainen@gmail.com
authors.forename: Henri
authors.initials: H
authors.lastname: Ruotsalainen
authors.forename: Kaisa
authors.initials: K
authors.lastname: Miettinen
authors.forename: Jan-Erik
authors.initials: JE
authors.lastname: Palmgren
authors.forename: Tapani
authors.initials: T
authors.lastname: Lahtinen
mesh_terms: D000465:Algorithms; D001918:Brachytherapy / Q000379:methods*; D003201:Computers; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D015233:Models, Statistical; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D012984:Software; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy