Recurrent atypical meningiomas: combining surgery and radiosurgery in one effective multimodal treatment

OBJECTIVE: Owing to their rarity and proteiform pathologic features, the clinical behavior of atypical meningiomas is not yet well characterized. Though the extent of resection is believed to be a key determinant of prognosis, limited data exist regarding optimal management of patients with recurrent disease. METHODS: In this 20-year retrospective case series, we reviewed the medical records of 46 patients with recurrent atypical meningiomas (185 lesions, 89 of which were local, 78 marginal, and 18 distant recurrences); treatment was radiosurgery (n = 60), surgery (n = 56), or both (n = 8). The median follow-up period was 53 months. Outcome measures were length of overall survival and disease-free intervals and prognostic factors for survival. RESULTS: Overall, the median progression-free survival was 26 months at the first recurrence and 100 months thereafter (the sum of the later intervals). Multivariate analysis showed that no treatment-related factors influenced prognosis, whereas recurrence at the skull base was a significant tumor-related factor limiting further treatment. Irrespective of treatment type, the recurrence-free interval was increasingly shorter during the clinical course, with a higher occurrence of marginal and distant lesions migrating to the midline and to the skull base. In sporadic cases, disease-free intervals were longer after wide craniotomy, tumor and dural resection with tumor-free margin. CONCLUSIONS: The disease-free interval was substantially similar after surgery and radiosurgery for treating recurrent disease in patients with atypical meningiomas. Surgery is the mainstay for prolonging survival, while radiosurgery can be an adjuvant strategy to gain time for clinical observation and planning aggressive surgical treatment.