Gliomas represent the most common primary malignant brain tumors in adults, with glioblastoma (WHO grade 4) being the most aggressive subtype. Despite advances in surgical techniques, radiotherapy, and chemotherapy, prognosis remains poor, particularly for high-grade gliomas. Maximal safe surgical resection is considered a cornerstone in the management of gliomas. Several studies suggest that a greater extent of resection (EOR) is associated with improved overall survival (OS) and progression-free survival (PFS), particularly in high-grade tumors. However, the benefit must be balanced against the risk of neurological deficits.

Postoperative chemoradiotherapy, particularly with temozolomide, has become the standard of care for high-grade gliomas. Despite this, the impact of EOR on outcomes in the context of adjuvant chemoradiotherapy remains a subject of ongoing investigation. This study aims to evaluate the prognostic significance of the extent of surgical resection in glioma patients who undergo postoperative chemoradiotherapy.

Inclusion Criteria:

• Adult patients (≥18 years) with histologically confirmed glioma (WHO grades 2-4) Underwent neurosurgical resection (gross total, subtotal, or biopsy only) Received postoperative radiotherapy with or without concurrent and/or adjuvant temozolomide Available pre- and post-operative imaging for EOR assessment Complete medical records and follow-up data

Exclusion Criteria:

• Recurrent gliomas at presentation Incomplete treatment (e.g., abandonment, death before adjuvant therapy) Lack of imaging or follow-up data

Adult patients (≥18 years) with histologically confirmed glioma (WHO grades 2-4)