Hyperthermia therapy is becoming accepted as the fourth major weapon in the arsenal of the cancer therapist. However, its transition into routine medical practice is being severely hindered by the lack of commercial equipment capable of selectively heating deep-seated. tumors to therapeutic temperatures.The goal of this research is to develop an effective, noninvasive hyperthermia system capable of locally heating a wide variety of cancer tumors located on or deep within (>10 cm) the body. Proposed is the development of a system that features a novel treatment applicator with the ability to dynamically vary both the spatial and temporal deposition of ultrasonic energy in response to measured temperature data. This is accomplished by simultaneously controlling, in real time, the acoustic frequency, power output, aperture, and focal length of a proprietary ultrasound transducer(s); the position and orientation of the transducer(s); and the temperature of a water bath through which the energy is transmitted and coupled to the body.Phase I of this project seeks to demonstrate the feasibility of the proposed system by modeling its heating performance when applied to a number of clinically significant situations. It is anticipated that the results of this study will reveal those operational parameters which have the greatest impact on heating, identify effective scanning/heating protocols, clarify the physiological and engineering limitations of the systems, and culminate in a preliminary product specification document.On the basis of the Phase I results, Phase II will request funding to develop the prototype deep-heating system and to conduct thermal dosimetry studies and clinical trials. From these investigations, it is expected that optimized treatment protocols will emerge that confirm the safety and efficacy of the device, thereby creating a demand for its commercialization.National Cancer Institute (NCI)