Location-Molecular Integrated Outcomes in 450 Cerebellar Glioma Microsurgical Cases

Microsurgical Outcomes and Prognostic Analysis of 450 Cases of Cerebellar Gliomas: Integrating Pathology, Molecular Biomarkers, and Novel Clinical Insights

The goal of this observational study is to learn if refined anatomical location-combined with molecular biomarkers-can predict surgical success and long-term survival in 450 adults and children with cerebellar gliomas who underwent microsurgical resection at a single center between 2014 and 2024. The main questions it aims to answer are:

1. Does tumor location (cerebellar hemisphere, vermis, fourth ventricle, or pontocerebellar-angle region) independently influence extent of resection and overall survival after adjustment for WHO grade and molecular profile?
2. Among IDH-wild-type low-grade gliomas, does gross-total resection plus early adjuvant radiotherapy improve 5-year overall and progression-free survival compared with lesser resection or radiotherapy omission?

Researchers compared four anatomical subgroups and multiple molecular subtypes (IDH, 1p/19q, MGMT, TERT, BRAF V600E) to quantify location-specific resection rates, complication rates, and survival outcomes. Participants underwent standardized pre-operative imaging, microsurgical resection with intra-operative monitoring when indicated, post-operative MRI within 48 h to quantify residual tumor, and longitudinal clinical and radiographic follow-up every 3-12 months for up to 10 years.

Inclusion Criteria

• Pathologically proven cerebellar glioma (hemisphere, vermis, fourth ventricle, or pontocerebellar-angle region) per 2021 WHO CNS classification
• First microsurgical resection performed at our center between January 2014 and January 2024
• Age ≥ 3 years at surgery
• Pre-operative Karnofsky Performance Status (KPS) recorded
• Availability of post-operative contrast MRI for resection-extent calculation
• Minimum required molecular data: IDH1/2 status (immunohistochemistry ± sequencing)
• Continuous follow-up ≥ 6 months after surgery (out-patient visits or telephone confirmation)

Exclusion Criteria

• Brain-stem glioma with secondary cerebellar invasion
• Recurrent or metastatic glioma
• Previous cranial radiation or glioma surgery at another institution
• Palliative resection (< 20 % of tumor volume removed)
• Missing post-operative MRI or insufficient tissue for mandatory IDH testing
• Follow-up < 6 months or lost to follow-up before 6-month landmark