Electromagnetic thermal therapy power optimization for multiple source applicators
- 1 January 1999
- journal article
- research article
- Published by Taylor & Francis in International Journal of Hyperthermia
- Vol. 15 (4) , 291-308
- https://doi.org/10.1080/026567399285666
Abstract
The optimization of power deposition for electromagnetic (EM) thermal therapy is investigated. Several goal or objective functions are examined using a generalized mathematical formulation. These include maximization of: (1) target power absorption, (2) the ratio of target to non-target power absorption, (3) target power absorption weighted by the ratio of target to non-target power absorption, and (4) target power absorption subject to the constraint that the non-target high power volume ('hot spot' volume) is below a chosen level. The merit of these functions was retrospectively tested using an anatomic data base containing 38 cancer patients that were clinically heated with EM phased arrays. CT and/or MRI image data were used to define relevant anatomic geometries and tissue properties for finite element numerical models. Power optimization is achieved by variation of seven available control parameters (four amplitudes and three phases) for these clinical array devices. The results indicate that site dependent improvements in target power absorption can be achieved using these goal functions relative to a configuration that utilizes equal phase and amplitude for the sources. The relative merit among these various functions favours an optimization strategy that maximizes the target power absorption weighted by the ratio of target power to non-target power absorption.Keywords
This publication has 14 references indexed in Scilit:
- Experimental investigation of an adaptive feedback algorithm for hot spot reduction in radio-frequency phased-array hyperthermiaIEEE Transactions on Biomedical Engineering, 1996
- SAR optimization in a phased array radiofrequency hyperthermia systemIEEE Transactions on Biomedical Engineering, 1995
- Finite element computation of electromagnetic fields [hyperthermia treatment]IEEE Transactions on Microwave Theory and Techniques, 1994
- Analysis and optimization of waveguide multiapplicator hyperthermia systemsIEEE Transactions on Biomedical Engineering, 1993
- Feasibility of estimating the temperature distribution in a tumor heated by a waveguide applicatorInternational Journal of Radiation Oncology*Biology*Physics, 1992
- Relationships among tumor temperature, treatment time, and histopathological outcome using preoperative hyperthermia with radiation in soft tissue sarcomasInternational Journal of Radiation Oncology*Biology*Physics, 1992
- Mathematical methods for treatment planning in deep regional hyperthermiaIEEE Transactions on Microwave Theory and Techniques, 1991
- Strategies for optimized application of annular-phased-array systems in clinical hyperthermiaInternational Journal of Hyperthermia, 1991
- Theoretical investigation of a phased-array hyperthermia system with movable aperturesInternational Journal of Hyperthermia, 1990
- Finite element solution of Maxwell's equations for hyperthermia treatment planningJournal of Computational Physics, 1985