Metamaterial-Assisted Miniaturized Antennas for Targeted Microwave Hyperthermia: From Deep Tissue Focus to Energy...

Microwave hyperthermia is a promising non-invasive tumor therapy, yet traditional energy-delivery antennas suffer from critical bottlenecks: bulkiness, shallow tissue penetration, uneven specific absorption rate distribution (SAR), and low energy efficiency. Metamaterials with artificially tailorable electromagnetic properties provide novel solutions to these challenges. This review focuses on metamaterial-assisted miniaturized antennas for targeted microwave hyperthermia, systematically elaborating on the electromagnetic hurdles in deep tissue heating, metamaterial-enabled mechanisms such as near-field control, SAR shaping and energy optimization, and two core systems: implantable and wearable. It also analyzes current technical bottlenecks such as complex manufacturing, inadequate SAR control, and immature feedback mechanisms, along with future trends including AI-driven design, reconfigurable metamaterials and millimeter-wave integration. Overall, this review aims to clarify how metamaterial-assisted antenna design can alleviate the trade-off between miniaturization and energy loss, improve treatment precision and safety, and promote the development of adaptive and clinically translatable microwave hyperthermia systems for solid tumors.