Feasibility investigation of low-cost microwave needle applicator for thermal ablation cancer therapy

Microwave (MW) applicators are widely used in medicine for thermal ablation / hyperthermia therapy in cancer treatment. Their goal is a proper local temperature increment of the irradiated tissue, allowing ablation or necrosis of tumoral cells. In this work, the design and fabrication of a low-cost mini-invasive needle applicator for hyperthermia cancer therapy is illustrated after the investigation of different optimization approaches. The applicator is composed by a coaxial antenna working in the Industrial, Scientific and Medical (ISM) frequency band at f=2.45 GHz. Several simulations and preliminary measurements are performed in order to investigate different geometries, different 3D printing materials, impedance matching techniques and radiating sections to fit 14 gauge (14 G) and 16 gauge (16 G) needle sizes. Moreover, a cooling system is considered to maintain the surrounding healthy tissue at lower temperature. A prototype has been constructed and characterized.