Application of optical spectroscopy in diagnosing and monitoring breast cancers: A technical review

Breast cancer is one of the most prevalent cancers among the global women population. It is due to the development of malignant cells in the breast tissue based on external or internal causes. The stages of detecting breast cancer include screening, diagnosis, and prognosis. Multiple imaging modalities, including digital Mammography, Ultrasonography, breast MRI, CT scan, and PET are applied for screening, diagnosis, identifying the stage of the tumor, classifying the developmental trend of the disease, and monitoring the treatment response. These modalities are commonly used in most fields of medicine, and have their merits and drawbacks. There are some optical technologies which have been developed in the diagnostic field. Optical imaging, and spectroscopy are known as real-time, sensitive, and non-invasive detecting approaches for human cancers in inaccessible locations, which use light propagation through the tissue to assess the optical properties. Optical techniques are used to measure optical and physiological properties of healthy breast tissue to discriminate abnormalities. Optical spectroscopy and fluorescence spectroscopy are some of the technologies for breast cancer detection. Such technologies can be combined with other modalities based on the capability of light guidance using optical fibers. Moreover, optical imaging offers potency for image-guided surgery. We review and discuss the broad range of methodologies and applications. Through a brief review of breast physiology, we discuss the various instrumental techniques and the related methods of optical spectroscopy and data analysis.