Time-Multiplexed Beamforming for Noninvasive Microwave Hyperthermia Treatment

• Published in: IEEE transactions on biomedical engineering Vol. 58; no. 6; pp. 1574 - 1584
• Main Authors: Zastrow, Earl, Hagness, Susan C., Van Veen, Barry D., Medow, Joshua E.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-06-2011; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adult; Applied sciences; Array signal processing; Beamforming; Biological; Biological and medical sciences; biomedical applications of electromagnetic (EM) radiation; Brain; brain cancer treatment; Brain modeling; Brain Neoplasms - radiotherapy; Cancer; Cancer therapies; Computational modeling; Detection, estimation, filtering, equalization, prediction; Electromagnetic heating; Exact sciences and technology; Female; finite-difference time-domain (FDTD) methods; Heating; Humans; Hyperthermia; Hyperthermia, Induced - methods; Information, signal and communications theory; Mathematical models; Medical sciences; microwave hyperthermia; Microwave theory and techniques; Microwaves; Models, Theoretical; Multiplexing; Neurology; Phantoms, Imaging; Radiotherapy Planning, Computer-Assisted - methods; Signal and communications theory; Signal Processing, Computer-Assisted; Signal, noise; Strategy; Studies; Telecommunications and information theory; Tumors of the nervous system. Phacomatoses; Nervous system diseases; finite-difference time-domain (FDTD) methods; brain cancer treatment; Brain cancer; microwave hyperthermia; Microwave; Time division multiplexing; biomedical applications of electromagnetic (EM) radiation; Numerical method; Malignant tumor; Electromagnetic wave; Beam forming; Cerebral disorder; Beamforming; Central nervous system disease; Signal processing; Hyperthermia; Cancer; Biomedical electronics; Biomedical engineering
• ISSN: 0018-9294; 1558-2531
• DOI: 10.1109/TBME.2010.2103943

A noninvasive microwave beamforming strategy is proposed for selective localized heating of biological tissue. The proposed technique is based on time multiplexing of multiple beamformers. We investigate the effectiveness of the time-multiplexed beamforming in the context of brain hyperthermia treatment by using a high-fidelity numerical head phantom of an adult female from the Virtual Family (IT'IS Foundation) as our testbed. An operating frequency of 1 GHz is considered to balance the improved treatment resolution afforded by higher frequencies against the increased penetration through the brain afforded by lower frequencies. The exact head geometry and dielectric properties of biological tissues in the head are assumed to be available for the creation of patient-specific propagation models used in beamformer design. Electromagnetic and thermal simulations based on the finite-difference time-domain method are used to evaluate the hyperthermia performance of time-multiplexed beamforming and conventional beamforming strategies. The proposed time-multiplexing technique is shown to reduce the unintended heating of healthy tissue without affecting the treatment temperature or volume. The efficacy of the method is demonstrated for target locations in three different regions of the brain. This approach has the potential to improve microwave-induced localized heating for cancer treatment via hyperthermia or heat-activated chemotherapeutic drug release.