Computer simulation and experimental studies of SAR distributions of interstitial arrays of sleeved-slot microwave antennas for hyperthermia treatment of brain tumors

The specific-absorption-rate (SAR) distributions produced by three-, six-, and seven-element arrays of sleeved-slot interstitial antennas in brain-equ ivalent tissues are investigated in this paper. Computer simulations of SAR distributions are compared to experimental measurement made in a brain-equ ivalent gel phantom at 2450 MHz. Results showed that a 15-mm antenna spacin g would produce SAR patterns with the least variation in its distribution c ompared to smaller or larger spacings. Moreover, the region of elevated SAR s is inscribed by the array and extends 35 mm in length to include the dist al antenna-tip region. In addition, results indicate that a hexagonal array configuration of either six or seven sleeved-slot interstitial antennas co uld provide elevated SARs in brain tissues. Since the six-element configura tion uses one less interstitial antenna with comparable SARs, it offers a b etter scheme for hyperthermia treatment of brain tumors.