Oligodendrogliomas in the CT/MR-era.

Area of Science:

• Neuro-oncology
• Neurosurgery
• Radiology

Background:

• Oligodendrogliomas survival data often stems from pre-CT/MR era studies.
• Modern histopathological classification and diagnostic tools were not utilized in older studies.
• Previous survival analyses did not account for tumor grade, potentially skewing results.

Purpose of the Study:

• To investigate survival times and prognostic factors for oligodendrogliomas in the CT/MR imaging era.
• To analyze survival data based on modern histopathological classification (WHO grading).
• To identify key prognostic factors influencing survival in different oligodendroglioma grades.

Main Methods:

• Retrospective study of 19 pure low-grade (LO) and 21 pure anaplastic (AO) oligodendrogliomas (WHO classification).
• Patients treated between 1987 and 1999 during the CT/MR era.
• Kaplan-Meier method for survival analysis; uni- and multivariate analyses for prognostic factors (Karnofsky Index, contrast enhancement, calcification, radiation therapy).

Main Results:

• Median survival for LO: 114 months; 5/10-year survival rates: 78.9%/44.1%.
• Median survival for AO: 21 months; 5/10-year survival rates: 23.8%/0.05%.
• Anaplastic oligodendrogliomas showed significantly poorer survival (p=0.0002). Higher Karnofsky Index, absence of contrast enhancement, and radiation therapy were associated with better survival in AO.

Conclusions:

• Survival times for oligodendrogliomas have not demonstrably improved in the CT/MR era compared to historical data.
• WHO grading is strongly associated with survival; prognostic factors must be evaluated separately for each grade.
• Higher Karnofsky Index, lack of contrast enhancement, and postoperative radiation therapy are positive prognostic indicators for anaplastic oligodendrogliomas.