Triangular lattice arrays for interstitial microwave hyperthermia

Implantable miniature microwave antennas operating between 300 and 2450 MHz have been employed to heat deep-seated tumors in hyperthermia cancer therapy. While the complete response rate has been reported to be as high as 80%, a major limitation of this procedure is that present antennas tend to give allow heating zone near the tip of the device. Thus, there is considerable interest in antennas with improved heating at the tip of the interstitial hyperthermia applicator. Previously, the authors reported microwave antennas for interstitial hyperthermia and thermocoagulation with maximal power deposition occurring near the tip of the antenna. Experimental results obtained at phantom measurements showed that heating peaks near the tip of the antenna. Indeed, power deposition was enhanced by six to ten times. In this paper, they report the development of a novel interstitial array configuration for use at 915 and 2450 MHz that better conforms to accessible, deep-seated tumor volume. It is based on the unique configuration of an equilateral triangle. The symmetry afforded by locating three identical interstitial antennas at the corners of the triangle will allow the triangular array geometry to serve as a basic building block with which to construct lattice array structures to effect uniform heating throughout the three-dimensional volume of the tumor