In this paper, the design and optimization of a low-cost needle microwave applicator for cancer therapy is illustrated. An adequately sized coaxial antenna inserted into a thin hypodermic needle, is optimized in the Industrial, Scientific and Medical frequency band (ISM) at f = 2.45 GHz. An extensive feasibility investigation is performed in order to obtain an efficient, mini-invasive and low-cost microwave medical device. Several technical solutions are explored and the optimization of a number of needle microwave applicators is performed. The performance of the applicators is evaluated in terms of antenna impedance matching, specific absorption rate (SAR), temperature distribution, and ablation zone sizes. After a comparison, a 14 gauge (14G) and a 16 gauge (16G) prototypes are fabricated and characterized.

The design and characterization of a low-cost mini-invasive needle applicator prototype for hyperthermia therapy of cancer are performed, after the investigation of different approaches, focused to increase the device feasibility and miniaturization and to improve patient wellness. The needle applicator is a coaxial antenna operating at frequency f = 2.45 GHz in the Industrial, Scientific, and Medical (ISM) frequency band. Many simulations are performed with the aim of investigating different geometries, impedance matching techniques, possible 3D-printing biocompatible materials, and radiating configurations fitting 14-gauge (14G) and 16-gauge (16G) hypodermic tube sizes. Also, a cooling circuit is investigated to maintain the patient healthy tissues at lower temperature, during the ablation session. As last step, prototypes of 14G and 16G applicators have been constructed and characterized.