The Art of Intraoperative Glioma Identification

Abstract

A major dilemma in brain-tumor surgery is the identification of tumor boundaries to maximize tumor excision and minimize postoperative neurological damage. Gliomas, especially low-grade tumors, and normal brain have a similar color and texture, which poses a challenge to the neurosurgeon. Advances in glioma resection techniques combine the experience of the neurosurgeon and various advanced technologies. Intraoperative methods to delineate gliomas from normal tissue consist of (1) image-based navigation, (2) intraoperative sampling, (3) electrophysiological monitoring, and (4) enhanced visual tumor demarcation. The advantages and disadvantages of each technique are discussed. A combination of these methods is becoming widely accepted in routine glioma surgery. Gross total resection in conjunction with radiation, chemotherapy, or immune/gene therapy may increase the rates of cure in this devastating disease.

Keywords: glioma; intraoperative; resection; technique; tumor.

Figure 1

In vivo stimulated Raman scattering microscopy images of human glioblastoma multiforme xenografts. (A) The arachnoidal and pial vessels on the surface of the normal brain were clearly identified in the standard bright field and stimulated Raman scattering images. Visualization of the tumor was undetectable under standard operative conditions. Certain regions of brain tissue that appeared grossly normal under bright field microscopy revealed extensive tumor infiltration on stimulated Raman scattering microscopy. The dashed line represents the tumor margin which was observed both biochemically and structurally. (B,C) The glioblastoma multiforme xenograft tissue was blue and cellular. (D) Normal axonal processes and vascular patterns were noted in non-infiltrated (normal) cortex. [Permission obtained from the publisher American Association for the Advancement of Science (AAAS); Ji et al. (63)].