Functional-Based Resection Does Not Worsen Quality of Life in Patients with a Diffuse Low-Grade Glioma Involving Eloquent Brain Regions: A Prospective Cohort Study

Highlights

• Functional-based resection of diffuse low-grade glioma does not worsen quality of life.

• Resection rates correlates positively with improved cognition and return to work rates.

• Resection rates correlates inversely with worsened postoperative cognition.

Objective

We assessed the impact of surgery on postoperative cognitive function and ability to work in adult patients with a diffuse low-grade glioma involving eloquent brain regions and having a functional-based maximal surgical resection using intraoperative corticosubcortical mapping under awake conditions.

Methods

We prospectively included 39 consecutive patients with diffuse isocitrate dehydrogenase–mutant low-grade glioma without preoperative and adjuvant oncologic treatment and assessed preoperative (mean, 24.1 ± 21.2 days before surgery) and postoperative (mean, 14.6 ± 13.2 months after surgery) cognitive evaluations and ability to work together with clinical, imaging, therapeutic, and follow-up characteristics before tumor progression.

Results

None of the 3 patients without preoperative cognitive deficit had postoperative worsening. We observed a significant inverse interaction between worsened postoperative cognitive function and extent of resection: 80.0%, 18.8%, and 16.7% of worsening after partial, subtotal, and total resection, respectively (P = 0.020). We observed an independent interaction between improved postoperative cognitive function and extent of resection: 20.0%, 43.7%, and 44.4% of improvement after partial, subtotal, and total resection, respectively (P = 0.022). Of the employed patients, 61.8% were unable to work preoperatively and 82.4% resumed their employment postoperatively (mean, 6.9 ± 5.5 months). We observed an independent interaction between postoperative ability to work, similar or superior to preoperative work capacity and extent of resection (P < 0.001): 20.0%, 87.5%, and 100% ability to work after partial, subtotal resection, and total resection.

Conclusions

The extent of the functional-based surgical resection and the residual tumor for diffuse low-grade gliomas involving eloquent brain regions correlate with postoperative cognitive outcomes and return to work rates.

Introduction

World Health Organization (WHO) diffusely infiltrative isocitrate dehydrogenase (IDH)-mutant grade II gliomas (diffuse low-grade gliomas [DLGGs])¹ affect young adults with an active family, professional, social, and occupational life.² DLGGs systematically progress3, 4 and induce epileptic seizures, neurologic deficits, and cognitive deficits, all impairing health-related quality of life and ability to work. Maximal safe surgical resection is the first therapeutic option, aiming at increasing survival and preserving, or even improving, health-related quality of life.5, 6, 7, 8, 9, 10, 11, 12

DLGGs located within eloquent regions pose a particular surgical challenge because of the higher risk of postoperative neurologic and cognitive deficits. This is an important issue because glioma survival, regardless of malignancy grade, is linked to the extent of resection and to the functional status of the patient.13, 14, 15, 16, 17 However, few studies have detailed the impact of a functional-based resection of a DLGG involving eloquent regions on postoperative health-related quality of life.18, 19, 20, 21 Although gross total resection is associated with improved health-related quality of life for patients with high-grade gliomas²² and with symptom resolution for patients with infiltrative gliomas,²³ no data are available about the relationship between the extent of functional-based resection, the residual tumor, and health-related quality of life in patients with a DLGG involving eloquent areas.

We assessed prospectively the postoperative cognitive function and ability to work as a surrogate of health-related quality of life in a series of adult patients with a DLGG involving eloquent areas and having a functional-based maximal surgical resection according to functional boundaries using intraoperative corticosubcortical mapping under awake conditions. Based on previous literature, we hypothesized that: 1) functional-based surgical resection does not worsen postoperative cognitive and neurologic evaluations of patients with a DLGG involving eloquent regions; 2) large functional-based surgical resection improves postoperative cognitive and neurologic evaluations of patients with a DLGG involving eloquent regions; and 3) large functional-based surgical resection improves postoperative ability to work of patients with a DLGG involving eloquent regions.