Evaluation of complex permittivity with band-spliced electronic terahertz technology and the application on paraffin embedded lung cancer samples

Histopathological cancer diagnosis conventionally relies on the examination of paraffin-embedded tissues. Terahertz (THz) technology has emerged as a promising avenue for expediting cancer diagnosis. This study focuses on evaluating the complex permittivity of lung cancer tissues in comparison to para-carcinoma tissues embedded in paraffin, utilizing electronic THz technology. The frequency range covers 0.11–1.1 THz, encompassing six independent bands spatially spliced together. The sample’s surface was meticulously flattened, and the scattering parameter matrix underwent thorough processing prior to permittivity inversion. Additionally, a specially designed sample fixture is implemented to enhance test accuracy. The empirical findings elucidate a consistent trend wherein the real part of the permittivity of each cancer tissue surpasses that of its corresponding para-carcinoma tissue. This pattern holds true across diverse types and locations of lung cancer sources. The deleterious impact of water-induced absorption of THz waves is mitigated through paraffin filling in tissue pores. Consequently, this reveals the nuanced influence of compositional and microstructural disparities between cancer and para-carcinoma tissues. The cancerous lesion induces alterations in the types and content of amino acids within the tissue samples. Leveraging the effective medium theory model to fit the permittivity spectra allows for a comprehensive representation of these discernible differences.