High-sensitivity flexible meta-surface for terahertz-based breast cancer differentiation: Study in cellular and fresh tissue

Abstract

Breast cancer is one of the most prevalent malignant tumors affecting women. Breast-conserving surgery (BCS) emerges as a secure and effective surgical approach. Terahertz (THz) technology proves advantageous in achieving real-time cancer edge detection during BCS, thanks to its label-free, non-ionizing, and real-time capabilities. In the THz frequency range, breast cancer tissue and normal tissue are indistinguishable due to their similar dielectric constants, which ultimately limits their use in surgical procedures. In this study, we introduced an innovative high-sensitivity meta-surface with an asymmetric slit ring. Through numerical simulations, the meta-surface was optimized to select the structure size with the highest sensitivity. The maximum sensitivity of the meta-surface reached as high as 448 GHz/RIU (f=2.25 THz). The flexible meta-surface show high sensing stability and robustness in 1000 bending cycles. We demonstrated that the THz meta-surface can improve the differentiation between breast cancer and normal breast cells. Meanwhile, combined with THz imaging, the designed meta-surface enhanced the contrast between breast cancer tissue and normal tissue by more than 50 %. This suggests that the strategy we proposed provides a theoretical basis for using THz technology based on meta-surfaces for clinical detection of cell types, and provides a rapid and effective method for doctors to identify whether the cancerous tissue has been completely removed during BCS.