Cranial Chordoma: A New Preoperative Grading System

Area of Science:

• Neurosurgery
• Oncology
• Pathology

Background:

• Chordomas are rare and complex skull base neoplasms.
• A preoperative grading system is needed to identify treatment areas and risk factors.
• Such a system can correlate with resection, complications, and recurrence.

Purpose of the Study:

• To propose a novel numerical grading system for cranial chordomas.
• To enable comparison of clivus chordoma cases.
• To statistically correlate the grading system with postoperative outcomes.

Main Methods:

• A numerical grading system (2-25 points) was developed, incorporating tumor size, site, vascular encasement, intradural extension, brainstem invasion, and recurrence.
• The system was applied to 42 cranial chordoma patients.
• Correlations were assessed with resection extent, operative stages, complications, recurrence, and survival.

Main Results:

• Three risk groups were identified: low (0-7), intermediate (8-12), and high (≥13).
• The grading system significantly correlated with resection extent (P < .002), operative stages (P < .014), recurrence (P = .03), Karnofsky Performance Status (P < .001), and overall outcome (P = .005).

Conclusions:

• The proposed grading system aids surgeons in predicting case difficulty for skull base chordomas.
• It helps identify areas requiring attention for further therapeutic planning.
• This system can improve management strategies for cranial chordomas.