Hybrid intelligent optimization of a circularly polarized microstrip antenna array for safe and effective hyperthermia cancer therapy.

Abstract

Hyperthermia therapy is a developing adjuvant oncologic technique that induces controlled heating (40-45 °C) in the affected area to enhance the therapeutic effect of radiation or chemotherapy, while avoiding damage to surrounding healthy tissue. In this work, a 16-element circularly polarized microstrip antenna array operating at 2.45 GHz is proposed to improve the accuracy and safety of electromagnetic hyperthermia treatment. Localization of the target is performed using image-based clustering. A particle swarm optimization (PSO)-based phase-only approach is used to optimize the beamformer weights for maximum power deposition at the tumor location. Hotspot suppression is performed using a Null Space Jacobian (NSJ)-based method to mitigate superficial heating after target localization and power optimization. This adaptive control is executed in a near real-time manner during treatment delivery, with a total closed-loop update time below 1.5 s. Simulation studies using a full-wave electromagnetic solver coupled with a bioheat model verify accurate power focusing, minimal energy leakage, and improved thermal safety. Phantom-based experimental validation further demonstrates uniform heating and effective suppression of non-target temperature rise. The proposed system demonstrates a hybrid intelligent approach for improving treatment efficacy and has strong potential for further development as an adaptive prototype verified through phantom experiments.