Neurosurgery for Brain Tumors: Update on Recent Technical Advances

Abstract

Advances in diagnostic imaging modalities and improved access to specialty care have led directly to an increased diagnosis of both metastatic and primary brain tumors. As technology has improved, so has the ability to treat this larger patient population. Diffusion tensor imaging (DTI) has recently shown the potential to aid in histologic diagnosis as well as to identify local brain invasion outside of that readily identifiable by conventional MRI. Similar to DTI, functional MRI provides a noninvasive means of delineating tumor margin from eloquent cortex and aids in preoperative surgical planning. As the literature shows increasing support for the advantages of extensive resection in glioma patients, modalities that aid in this regard are displaying increased importance. Surgeons have recently demonstrated the utility of intraoperative MRI in increasing extent of resection in both low- and high-grade glioma patients. Intraoperative tumor fluorescence provided by the chemical compound 5-aminolevulinic acid assists surgeons in identifying the true tumor margin during resection of glial neoplasms consequently increasing extent of resection. Finally, laser interstitial thermal therapy is an emerging treatment modality allowing surgeons to treat small intracranial lesions with potentially decreased morbidity via this minimally invasive approach. The following review analyzes the recent literature in an effort to describe how these modalities can and should be used in the treatment of patients with intracranial pathology.

IDH1 Overexpression Induced Chemotherapy Resistance and IDH1 Mutation Enhanced Chemotherapy Sensitivity in Glioma Cells in Vitro and in Vivo

“…Despite of aggressive methods of surgery, radiotherapy and chemotherapy, GBMs are invariably associated with unavoidable tumor recurrence and overall poor prognosis. The overall survival of patients with GBMs is only 12-15 months (Stupp et al, 2005;Wen et al, 2008;Buonerba et al, 2011;Sherman et al, 2011;Babu et al, 2012). Prognosis is even poorer in elderly GBM patients.…”

Intraoperative stereotactic injection of Indigo Carmine dye to mark ill-defined tumor margins: a prospective Phase I–II study

“…3,17,22 Intraoperative MRI is clearly the most reliable method for determining tumor margins during surgery. However, the equipment is expensive (approximately $3 million) 20 and therefore is only available in few institutions. Moreover, intraoperative MRI requires specialized equipment and room shielding, and it introduces certain limitations for the surgeon because some surgical instruments or equipment are not available in MRI-compatible versions.…”

“…12 Intraoperative MRI presents a potential solution, but the cost is often prohibitive. 20 Tumor-specific dyes are not readily available in the United States, and the interpretation and significance of vague fluorescence can be ambiguous without sophisticated quantitative measurements (http://www.cancer.gov/ clinicaltrials/search/view?cdrid=674659&version=Health Professional).…”

Review of Neurosurgical Fluorescence Imaging Systems for Clinical Application

“…Intraoperative visualization of diffusely invasive tumor lesions with a surgical microscope is also a major challenge [17]. Several kinds of intraoperative image-guided surgical techniques for glioma have been developed, e.g., neuronavigation, ultrasonography, MRI, and fluorescence-guided surgery [18][19][20][21][22]. 5-ALA is the most studied and the most used of the various fluorescent tumor markers for fluorescenceguided surgery.…”