Terahertz pulsed imaging of basal cell carcinoma ex vivo and in vivo

Background Terahertz radiation lies between the infrared and microwave regions of the electromagnetic spectrum and can be used to excite large amplitude vibrational modes of molecules and probe the weak interactions between them. Terahertz pulsed imaging (TPI) is a noninvasive imaging technique that utilises this radiaton. Objectives To determine whether TPI could differentiate between basal cell carcinoma (BCC) and normal tissue and to test whether it can help facilitate delineation of tumour margins prior to surgery. Methods A portable TPI system was used in the clinic to image 18 BCCs ex vivo and five in vivo. Results The diseased tissue showed a change in terahertz properties compared with normal tissue, manifested through a broadening of the reflected terahertz pulse. Regions of disease identified in the terahertz image correlated well with histology. Conclusions This study has confirmed the potential of TPI to identify the extent of BCC in vivo and to delineate tumour margins. Further clinical study of TPI as a surgical tool is now required.