gms | German Medical Science

Objective: Despite the advances in skull base surgery, radical microsurgical resection of cavernous sinus meningiomas (CSM) is associated with high cranial nerve and vascular morbidity. A conservative therapeutic approach appears to be more suitable for this subgroup of meningiomas. We present a series of 24 patients with meningiomas involving the cavernous sinus (CS), who received a combined treatment of surgery and fractionated stereotactic radiation therapy (FSRT).

Methods: From 2006 to 2012 24 patients underwent surgery for a menigioma involving the CS and received an adjuvant FSRT. Surgical approach and extent of resection was planned preoperatively according to the tumor origin and the tumor extension. Meningiomas were divided into 2 groups. Group 1 consisted of primary cavernous sinus meningiomas with or without extension outside the CS and group 2 of meningiomas with secondary CS invasion. Tumor volume and neurological deficits were evaluated during regular follow-up visits.

Results: Our series includes 19 women and 5 men. Biopsy only was performed in 8 tumors, whereas near total or subtotal resection of the extracavernous portion of the tumor with or without decompression of cranial nerves in 16 cases. There was no perioperative mortality. Histological examination revealed a WHO grade I meningioma in 21 patients and an atypical meningioma in 1 patient. In 2 cases histological confirmation was not possible and the diagnosis was determined by typical imaging criteria and intraoperative findings. All patients received a FSRT 1 to 40 months following surgery (mean 4,5 months). Median total dose was 50,4 Gy with 1,8 Gy per fraction. Two international patients were lost to follow up. Two-year follow up was available in 20 patients. The last follow-up was available at a mean of 62,5 months (6-120 months). Deterioration of IIIrd cranial nerve function was evident in 5 patients after surgery. In 5 patients improvement of pre-existing neurological deficits was observed. No late toxicity grade II or higher was seen. Tumor control was achieved in 21/22 patients. One patient had tumor progression of the extracavernous residual tumor 96 months after combined treatment. In 6/22 patients partial remission of tumor remnant was observed.

Conclusion: Meningiomas involving the cavernous sinus are a challenging subtype of meningiomas. A combined treatment of accurately planned surgery and radiotherapy can provide a sufficient tumor growth control avoiding the high mortality of radical surgical resection.