SBIR-STTR Award

The overall goal of this project is to complete development and to test a novel ultrasonic tapered linear phased array applicator for hyperthermia treatment. Such an applicator will allow electronic steering of the focus along a desired path without the use of a mechanical scanning system; it will also remain fixed relative to the patient, making coupling easier. The applicator will be computer controlled such that the scan path and/or intensity can be altered at any time during treatment to maintain a constant uniform temperature. Such a system is expected to meet the requirements for controlled local hyperthermia treatment of deep-seated tumors. Each element of the phased array applicator (64 in all) will be driven by a modular high-power multichannel RF generator similar to that used in the URI Therm-X, Inc. Sonotherm 1000 ultrasound hyperthermia system.Initial testing of the applicator will consist of experimentally acquiring field plots and comparing them to the theoretically predicted plots. When the experimental phased array applicator is generating fields as expected theoretically and these fields seem to be adequate for hyperthermia applications, tests on phantoms will be initiated. Finally, the performance of the prototype applicator that electronically scans its focus will be compared to that of a mechanically scanned, fixed focus applicator for various scan patterns. If the proposed prototype ultrasonic phased array applicator exhibits heating performance and control commensurate with clinical needs, Phase II development will be devoted to the construction and animal testing of a prototype system in preparation for trials.National Cancer Institute (NCI)

This research seeks to continue development of a novel, ultrasound phased-array applicator and control system that employs phase and frequency modification to electronically steer a focused ultrasonic beam in three dimensions for hyperthermia delivery. As a part of the development, work will continue on the applicator and control system in terms of its specification for heating targeted volumes of tissue. The refinement of large-aperture array fabrication and construction techniques to improve reliability and ease of assembly, to reduce costs, and to provide the means of alignment necessary for clinical utility will be included.In addition, a criteria for specifying the path and dwell time of the beam focal region to produce a uniformly heated volume will be defined, and a strategy for the placement of temperature-monitoring probes to act as control points will be developed. Finally, enhanced methods for therapy planning using various imaging and temperature probe insertion and localization techniques will be investigated to provide the therapy preparation methodologies necessary for practical clinical implementation of the system.

Anticipated Results:
The commercial potential of this work is based upon the demonstrated effectiveness of hyperthermia for cancer therapy and the present lack of sophisticated heating systems capable of three-dimensional control of a heating beam deep within the body. This system is designed to heat deeply seated tumors while sparing intervening and surrounding normal tissue. Such devices are not commercially available at present, though their need in the clinical environment is well known.National Cancer Institute