[Characterization of helical coil microwave antenna for interstitial hyperthermia]

Implantable microwave antennas for interstitial hyperthermia have been constructed by using a fine wire helical coil extension of the coax feedline inner conductor. The effects of the variable coil length the winding density, and the antenna insertion depth in the tissue on the heating patterns from a single antenna were characterized in phantom models. Results indicated that the helical coil microwave antenna provided localized heat at depth near the antenna tip, and the heating patterns were easily modified by minor changes in the coil length, winding density, and altering the separation gap. The characteristics of the helical coil microwave antenna may increase its potential application to cases of interstitial hyperthermia.