Noninvasive microwave phased arrays for local hyperthermia: a review

Microwave energy has proven useful for treating superficial tumours in the head, neck and chest regions. Currently, multi-element phased arrays are being proposed to upgrade clinical capabilities for localized microwave hyperthermia. When compared with a single radiating element, phased array applicators are expected to provide deeper tissue penetration, reduce undesired heating of normal tissues between the applicator and tumour, and improve local control of the tumour temperature distribution. This paper surveys recent developments in the design and characterization of phased arrays, identifies anatomical and physiological factors that complicate successful clinical treatment and discusses the current state of phased array hardware development for hyperthermia.