Direct Comparison of Gamma Knife Radiosurgery and Microsurgery for Small Size Meningiomas

Area of Science:

• Neurosurgery
• Radiation Oncology
• Oncology

Background:

• Small intracranial meningiomas (<3 cm) present treatment dilemmas: observation versus intervention.
• Intervention options include microsurgery or radiosurgery, typically employed upon tumor progression.
• Predictors of unfavorable outcomes require identification for personalized treatment strategies.

Purpose of the Study:

• To compare local tumor growth control and recurrence-free survival (RFS) between microsurgical resection and Gamma Knife radiosurgery (GKRS) for small intracranial meningiomas.
• To identify predictors of unfavorable outcomes in patients treated for small intracranial meningiomas.

Main Methods:

• Retrospective review of 90 patients with intracranial meningiomas treated between 2005-2016.
• Comparison of outcomes between microsurgery (n=31) and GKRS (n=59).
• Clinical and radiographic evaluations post-treatment to assess outcomes.

Main Results:

• GKRS demonstrated significantly higher local tumor control rates at 5 and 10 years post-treatment compared to microsurgery (P=0.02 and P=0.003, respectively).
• Median recurrence-free survival (RFS) was significantly longer in the GKRS group versus the microsurgery group (P=0.04).
• No significant difference in RFS was observed between GKRS and Simpson grade I microsurgical resection (P=0.69). Preoperative Karnofsky performance scale score ≤70 was the sole predictor of unfavorable outcome in multivariate analysis.

Conclusions:

• GKRS provides high tumor control rates and extended RFS, comparable to Simpson grade I resection for small meningiomas.
• Subtotal resection is not recommended for small meningiomas due to suboptimal outcomes.
• Treatment decisions should be individualized based on patient comorbidities and overall benefit.