Advancement of Near Infrared techniques in diagnosis and treatment of cancer

Abstract

Near-Infrared photoimmunotheraphy (NIR-PIT) is newly developed therapy for cancer treatment, by using a specific monoclonal antibody (mAb) conjugated to a photoactive agent i.e. IRDye 700DX. In this technique, the conjugate of specific monoclonal antibody - photoactive agent is administered intravenously to cancer patient. When NIR light is applied, the monoclonal antibody - photoactive agent conjugate (APC) is excited and selectively kill the cancer cell without harming neighbouring normal cell. NIR light alters the chemical structure of APC and damages the cancer cell membrane. For the diagnosis of tumor, it is possible to observe the movements of erythrocyte in tissues by using diffuse correlation spectroscopy (DCS). DCS flow measurements are carried out by observing photon speckle variations induced by moving tissue scattering. Another diagnostic tool is Near-infrared spectroscopy (NIRS), which is based on endogenous chromophores difference between healthy tissue and cancer by using diagnostic indicator i.e. oxy-haemoglobin or deoxyhaemoglobin, lipid or water bands. NIRS is being used in a variety of biological and pharmaceutical research fields, including brain imaging, cardiovascular radiology, formulation and quality/process control, and even clinical trial. In this review article, we describe the Near-Infrared photoimmunotheraphy (NIR-PIT) with its mechanism, role of DCS & NIRS in cancer diagnosis and various application of NIR-PIT.
 Keyword: Near-infrared immunotherapy (NIR-PIT); diffuse correlation spectroscopy (DCS); Near-infrared spectroscopy (NIRS); Cancer treatment; Cancer diagnosis.