The use of microwave, millimeter wave and terahertz spectroscopy for the detection, diagnostics and prognosis of breast cancer

We have analyzed the broadband dielectric properties of cancerous and non-cancerous tissues were analyzed at the microwave, millimeter wave, and terahertz frequencies. In-vitro measurements were obtained using the vector network analyzer-based coaxial probe (2 - 50 GHz), backward-wave oscillator-based free space quasi-optical spectroscopy (30-120 GHz), and dispersive Fourier transform spectroscopy methods (60 -1.5 THz). All three techniques were modified to yield the complex real and imaginary permittivity, absorption coefficient, refractive index, and transmission data over an extended frequency range from 2 GHz to 1,500 GHz. The results reveal the characteristic signatures of breast tissues and display a significant difference in the electromagnetic response of cancerous (malignant) and non-cancerous (benign) tissues. All three techniques provide prospects for extending in-vitro measurements to in-vivo breast cancer detection and diagnostics.