Extent of resection classification

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• Early postoperative seizures in patients with adult-type diffuse gliomas: Incidence, risk factors, and clinical outcomes
• Proliferation-Diffusion Modeling in Glioblastoma: Impact of Supramaximal Resection on Survival
• A Multicenter Study on Intraoperative Glioma Grading via Deep Learning on Cryosection Pathology
• Imaging features and consideration of progression pattern of diffuse hemispheric gliomas, H3 G34-mutant
• Safety and Efficacy in the Transcortical and Transsylvian Approach in Insular High-Grade Gliomas: A Comparative Series of 58 Patients
• Prognostic revalidation of RANO categories for extent of resection in glioblastoma: a reconstruction of individual patient data

Definition: Complete removal of the visible and identifiable tumor.

Usage: General term, sometimes used interchangeably with Gross Total Resection, though may imply a broader removal (including microscopic disease).

Limitation: May overstate if no imaging or histological confirmation is done.

Definition: Only a portion of the tumor is removed.

Indications: Tumor is infiltrative, near eloquent brain areas, or patient cannot tolerate longer surgery.

Outcome: Generally associated with lower survival/progression-free survival rates compared to more extensive resections.

Definition: 100% removal of contrast-enhancing tumor on postoperative imaging (usually MRI with gadolinium).

Goal: Remove all visible tumor on imaging, not necessarily microscopic infiltration.

Limitation: Microscopic disease may remain, especially in gliomas.

Definition: Remove as much tumor as possible without causing significant neurological deficit.

Principle: Balance between oncological benefit and functional preservation.

Common Practice: Used especially in gliomas or tumors near eloquent areas (motor cortex, speech centers, etc.).

Definition: >90–95% of tumor removed, but small residual remains (often due to risk of damage to critical areas).

Imaging: Tiny enhancing remnant visible on postop scan.

Use: Common compromise when Gross Total Resection risks too much morbidity.

Definition: Less than Gross Total Resection, often <90% tumor removal.

Cause: Tumor location, size, vascularity, or infiltration into eloquent brain.

Prognosis: Intermediate between biopsy/partial and GTR.

Definition: Resection goes beyond the enhancing tumor margins, including removal of surrounding non-enhancing T2/FLAIR abnormality.

Goal: Target potential microscopic infiltration—especially in high-grade gliomas.

Benefit: Shown in some studies to improve survival, but with increased risk if not carefully planned.

Definition: Surgical removal of areas of FLAIR hyperintensity on MRI (often non-enhancing, infiltrative parts of gliomas).

Specific to: Diffuse gliomas, particularly IDH-mutant gliomas where FLAIR abnormalities correlate with tumor infiltration.

Relation to Supramaximal: FLAIRectomy is a type of supramaximal resection.

Challenge: Differentiating between tumor infiltration and peritumoral edema or gliosis.

Total resection

Partial resection

Gross total resection (GTR)

Maximal safe resection

Near total resection (NTR)

Subtotal resection

Supramaximal resection.

FLAIRectomy

see Kobayashi tumor removal grading system.