Adjuvant radiotherapy for atypical meningiomas

Area of Science:

• Neurosurgery
• Radiation Oncology
• Pathology

Background:

• Atypical meningiomas (AMs) are rare tumors requiring effective treatment strategies.
• Optimal treatment for AMs, balancing efficacy and toxicity, remains an area of investigation.

Purpose of the Study:

• To compare outcomes for atypical meningiomas (AMs) treated with surgery alone versus surgery plus radiotherapy.
• To evaluate the impact of adjuvant radiotherapy at initial diagnosis or first recurrence on local control and survival.

Main Methods:

• Retrospective review of 59 patients with 63 AMs treated between 1991 and 2014.
• Analysis of local control (LC), overall survival (OS), Karnofsky Performance Status (KPS), and toxicity.
• Kaplan-Meier and log-rank tests used for statistical analysis of LC and OS.

Main Results:

• Adjuvant radiotherapy significantly improved median time to local failure (TTLF) to 180 months compared to 46 months with surgery alone (p=0.02).
• This benefit persisted even for Simpson Grade I-III resections (median TTLF 180 vs. 46 months, p=0.002).
• Treatment at first recurrence showed a shorter median TTLF (26 months) compared to initial diagnosis (48 months, p=0.007).

Conclusions:

• Adjuvant radiotherapy is beneficial for improving local control in atypical meningiomas (AMs).
• The addition of radiotherapy, even after subtotal resection (Simpson Grade I-III), confers a local control advantage.
• Aggressive initial treatment is crucial due to the challenges in controlling recurrent disease.