Strategies to maximize resection of complex, or high surgical risk, low-grade gliomas

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>Early and aggressive resection of low-grade gliomas (LGGs) leads to increased overall patient survival, decreased malignant progression, and better seizure control. This case series describes the authors' approach to achieving optimal neurological and surgical outcomes in patients referred by outside neurosurgeons for stereotactic biopsy of tumors believed to be complex or a high surgical risk, due to their diffuse nature on neuroimaging and their obvious infiltration of functional cortex.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Seven patients underwent individualized neuroimaging evaluation preoperatively, which included routine brain MRI with and without contrast administration for intraoperative neuronavigation, functional MRI with speech and motor mapping, diffusion tensor imaging to delineate white matter tracts, and MR perfusion to identify potential foci of higher grade malignancy within the tumor. Awake craniotomy with intraoperative motor and speech mapping was performed in all patients. Tumor removal was initiated through a transsylvian approach for insular lesions, and through multiple corticotomies in stimulation-confirmed noneloquent areas for all other lesions. Resection was continued until neuronavigation indicated normal brain, cortical or subcortical stimulation revealed functional cortex, or the patient began to experience a minor neurological deficit on intraoperative testing.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Gross-total resection was achieved in 1 patient and subtotal resection (&gt; 80%) in 6 patients, as assessed by postoperative MRI. Over the average follow-up duration of 31 months, no patient experienced a progression or recurrence. Long-term seizure control was excellent in 6 patients who achieved Engel Class I outcomes. Neurologically, all 7 patients experienced mild temporary deficits or seizures that completely resolved, and 1 patient continues to have mild expressive aphasia.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Significant resection of diffuse, infiltrating LGGs is possible, even in presumed eloquent cortex. Aggressive resection maximizes seizure control and does not necessarily cause permanent neurological deficits. Individualized preoperative neuroimaging evaluation, including tractography and awake craniotomy with intraoperative speech and motor mapping, is an essential tool in achieving these outcomes.</jats:p></jats:sec>

Socioeconomic restraints and brain tumor surgery in low-income countries

“…It has become relatively standard practice in Western institutions to use frameless stereotaxy or other forms of image guidance in brain tumor surgery, and studies have shown the increased gross-total resection outcomes and decreased morbidity facilitated by image guidance. 8,32 However, in our study image guidance was used in only 2 cases of glioma situated near eloquent cortex, and the equipment was rented from an outside facility that supplies several hospitals instead of being owned. A number of studies over the past decade have also highlighted the value of high-power 1.5-T or 3-T MRI in the improvement of extent of resection while minimizing postoperative morbidity in patients with intraaxial tumors; although low-power intraoperative MRI may be more economical, studies did not show significant value for its use in intraaxial tumor resection.…”

“…A number of studies over the past decade have also highlighted the value of high-power 1.5-T or 3-T MRI in the improvement of extent of resection while minimizing postoperative morbidity in patients with intraaxial tumors; although low-power intraoperative MRI may be more economical, studies did not show significant value for its use in intraaxial tumor resection. 8,14,32 Unfortunately, we were unable to use intraoperative MRI in any of our patients due to its very high cost and setup requirements.…”

“…8,14 According to the World Bank, Egypt is considered a lower-to middle-income country. 32 Limited data are available from developing countries to be able to assess their current treatment strategies, 16,20 due to the absence or inefficiency of their brain tumor registries. Accordingly, it was essential to raise the question of whether the application of recent technological advances such as intraoperative MRI, image guidance, and other techniques in routine day-today practice is beneficial in attaining good outcomes.…”

Expression of p16 and Survivin in gliomas and their correlation with cell proliferation

“…Clinical studies have revealed that gliomas with identical classifications may react differently to the same treatment (12). Furthermore, prognoses, as well as the infiltration, recurrence and metastasis of the tumor, differ (13). Studies have confirmed that differences amongst gliomas with identical histological subtypes are due to alterations in gene expression.…”

Intraoperative Monitoring with Cortical Estimulation

“…The correct surgical planning for radical resection of gliomas allows a better quality of life and increases patient survival 13,[24][25][26][27][28] . However, there is a potentially high risk of permanent sequelae, particularly when the tumor is located within eloquent brain regions.…”