Optical fiber-probe spectroscopy of brain tumors

In the current clinical scenario, surgical resection of tumors remains the front-line treatment modality for the management of abnormalities in both brain and central nervous system. The primary goal of surgery is to remove as much tumor as possible sparing the normal tissue. Needless removal of normal brain tissue could lead to detrimental neurological deficits causing cognitive dysfunction and motor impairment. Surgical biopsy and other imaging modalities have the disadvantages of being invasive and time-consuming, and brain shift is a major problem when using preoperative magnetic resonance images. Alternately, in the recent years, optical spectroscopy has emerged as a diagnostic modality for the detection of abnormalities in the brain. The resulting spectral features from tissues can provide information related to the biochemistry, morphology, and physiological conditions of the tissue. This technique can probe tissues in vivo or minimally invasive, and real time. In this chapter, after having covered current diagnostic modalities used in pediatric neuro-surgery, a brief outline on the fundamentals of different spectroscopic techniques is explained in detail. In the following section, a brief description of fiber optic probes and different fiber probe configurations implemented in an optical spectroscopic system is presented. Additionally, details related to different methods for spectral analysis are also discussed. Next, we review the different optical point spectroscopic modalities for the demarcation of abnormalities in the pediatric brain. We finally conclude with a discussion on promises, hopes, and opportunities of this emerging technology in the neuro-oncological application.