Metamaterial Antenna Arrays for Improved Uniformity of Microwave Hyperthermia Treatments

2 Abstract |Current microwave hyperthermia applicators are not well suited for uniform heating of large tissue regions. The objective of this research is to identify an optimal microwave antenna array for clinical use in hyperthermia treatment of cancer. For this aim we present a novel 434 MHz applicator design based on a metamaterial zeroth order mode resonator, which is used to build larger array congurations. These applicators are designed to effectively heat large areas extending deep below the body surface and in this work they are characterized with numerical simulations in a homogenous muscle tissue model. Their performance is evaluated using three metrics: radiation pattern-based Effective Field Size (EFS), temperature distribution-bas Therapeutic Thermal Area (TTA), and Therapeutic Thermal Volume (TTV) reaching 41{45 ◦ C. For 2 � 2 and 2 � 3 array congurations, the EFS reaching > 25% of maximum SAR in the 3.5 cm deep plane is 100% and 91% of the array aperture area, respectively. The corresponding TTA for these arrays is 95% and 86%, respectively; and the TTV attaining > 41 ◦ C is over 85% of the aperture area to a depth of over 3 cm in muscle, using