Analytical Fitting of Dielectric Response of Basal Cell Carcinoma

Terahertz spectroscopy and imaging are non-ionizing and non-invasive tools to investigate skin and its associated tumoral pathologies. It is therefore necessary to accurately describe the dielectric response of both skin and basal cell carcinoma in the THz range. Due to the high sensitivity of THz radiation to polar substances and the significant water content in the skin, the traditional model to describe its dielectric permittivity has been the double Debye one. This paper shows that a third order Cole-Cole model has the potential to accurately approximate the dielectric permittivity of both skin and basal cell carcinoma. We fitted experimental data taken from the literature using a genetic algorithm routine and we found a minimum root-mean-square error of 0.0466, which is approximately two order of magnitude less than the dielectric permittivity. The proposed third order Cole-Cole model could be used to advance THz-based technologies for skin cancers diagnosis.