Optical biopsy for the diagnosis of breast tumors

Elastic scattering or spectroscopy offers the possibility of distinguishing between cancerous and non-cancerous tissue in suspicious breast lumps with a relatively simple optical measurement. The measurement of the relative reflection of light has previously been shown to be sensitive to both the size and distribution of intra and inter-cellular structures as well as absorption from chromophores present in the tissue. Coupling a white light source and spectrometer to optic fibres makes it possible to construct probes that can be inserted through the skin or used during the operation or on excised tissue such as the sentinel node. This `optical biopsy' is correlated with a conventional histopathological specimen obtained at the same point. Spectra have been obtained from a large number of patients with benign and malignant lesions. Some of the differences that appear in these spectra have been identified and these are discussed. To a relatively high degree of sensitivity and specificity it is shown to be possible to distinguish between malignant tumours, benign lesions and normal tissue.