Insular glioma surgery: an evolution of thought and practice

OBJECTIVEThe goal of this article is to review the history of surgery for low- and high-grade gliomas located within the insula with particular focus on microsurgical technique, anatomical considerations, survival, and postoperative morbidity.METHODSThe authors reviewed the literature for published reports focused on insular region anatomy, neurophysiology, surgical approaches, and outcomes for adults with World Health Organization grade II-IV gliomas.RESULTSWhile originally considered to pose too great a risk, insular glioma surgery can be performed safely due to the collective efforts of many individuals. Similar to resection of gliomas located within other cortical regions, maximal resection of gliomas within the insula offers patients greater survival time and superior seizure control for both newly diagnosed and recurrent tumors in this region. The identification and the preservation of M2 perforating and lateral lenticulostriate arteries are critical steps to preventing internal capsule stroke and hemiparesis. The transcortical approach and intraoperative mapping are useful tools to maximize safety.CONCLUSIONSThe insula's proximity to middle cerebral and lenticulostriate arteries, primary motor areas, and perisylvian language areas makes accessing and resecting gliomas in this region challenging. Maximal safe resection of insular gliomas not only is possible but also is associated with excellent outcomes and should be considered for all patients with low- and high-grade gliomas in this area.

Evidence for Improving Outcome Through Extent of Resection

Surgical resection plays a central role in the management of gliomas however many tumors are within areas resulting in sensorimotor and cognitive consequences. This article reviews the evidence in support of extent of resection to improve survival, symptom management, and time to malignant transformation in low-grade gliomas. The authors summarize the evolving literature regarding the role of maximal safe resection in light of WHO subclassification of low-grade gliomas. Long lasting neurological deficits following glioma resection may hinder both survival and quality of life. New insights into glioma related central nervous system plasticity impact both surgical planning and timing of interventions.

Molecular genetics of low-grade gliomas: genomic alterations guiding diagnosis and therapeutic intervention. 11th annual Frye-Halloran Brain Tumor Symposium

OBJECT

The authors' goal was to review the current understanding of the underlying molecular and genetic mechanisms involved in low-grade glioma development and how these mechanisms can be targets for detection and treatment of the disease and its recurrence.

METHODS

On October 4, 2012, the authors convened a meeting of researchers and clinicians across a variety of pertinent medical specialties to review the state of current knowledge on molecular genetic mechanisms of low-grade gliomas and to identify areas for further research and drug development.

RESULTS

The meeting consisted of 3 scientific sessions ranging from neuropathology of IDH1 mutations; CIC, ATRX, and FUBP1 mutations in oligodendrogliomas and astrocytomas; and IDH1 mutations as therapeutic targets. Sessions consisted of a total of 10 talks by international leaders in low-grade glioma research, mutant IDH1 biology and its application in glioma research, and treatment.

CONCLUSIONS

The recent discovery of recurrent gene mutations in low-grade glioma has increased the understanding of the molecular mechanisms involved in a host of biological activities related to low-grade gliomas. Understanding the role these genetic alterations play in brain cancer initiation and progression will help lead to the development of novel treatment modalities than can be personalized to each patient, thereby helping transform this now often-fatal malignancy into a chronic or even curable disease.