Laser induced breakdown spectroscopy for the diagnosis of several malignant tissue samples

Here, the authors have utilized laser induced breakdown spectroscopy (LIBS) to distinguish cancerous tissues from normal ones. For this purpose, the plasma emission spectra of the normal and cancerous tissues taken from four different organs of interest, i.e, breast, colon, larynx, and tongue are analyzed via the excitation of a pulsed Neodymium-doped Yttrium Aluminum Garnet (ND: YAG) laser at 1064 nm. Results show that the abundance of the trace elements such as Ca, Mg, and Na trace elements are elevated in the cancerous tissues with respect to normal ones. In addition, inductively coupled plasma-optical emission spectroscopy and quadrupole-mass spectroscopy are employed to support the findings given by LIBS. Furthermore, the plasma characteristics such as temperature and electron density are probed by data processing of the plasma spectra at local thermal equilibrium condition as an alternative technique to discriminate between the normal and malignant tissues. It is shown that more energetic plasma is created on the neoplastic specimens resulting in higher electron density and plasma temperature due to the corresponding intense atomic/ionic characteristic emissions of species. The simplicity and low cost of processes benefits the physicians to encourage the clinical application of LIBS in near future. (C) 2017 Laser Institute of America.