Gamma Knife Radiosurgery for Meningiomas of the Confluence of the Falx and Tentorium

Introduction + Hypothesis: Confluence of the falx and tentorium (CFT) meningiomas are both rare and challenging to manage due to proximity to critical venous and neural structures. Gamma Knife radiosurgery (GKRS) is a potential management strategy both as an adjuvant and as a primary modality. Here, we report the largest series focused exclusively on the outcomes of GKRS for CFT meningiomas.

Methods: Of 2,031 patients who underwent GKRS for meningioma at our institution between 1987 and 2021, 23 patients (1.1%) had CFT meningioma, of which 3 had neurofibromatosis type 2 (excluded for analysis). Tumor control, overall survival (OS), and complications were recorded and analyzed. The median tumor margin dose was 13 Gy at the 50% isodose line. The median tumor volume treated was 4.4 cc (IQR: 3.5–7.7). The median patient age was 58 years (range: 33–83), the median MRI surveillance duration was 59 months (IQR: 34–92), and the median overall follow-up duration was 92 months (IQR: 42–201).

Results: At 5 and 10 years, local tumor control rate was 100% (N = 10) and 83% (N = 4), respectively. Tumor volume regressed in 11 patients and was stable in 8. One patient had delayed progression at 7.5 years after two operations and GKRS and was retreated. No adverse radiation effects were observed. The 5- and 10-year OS were 100% (N = 13) and 100% (N = 7).

Conclusions: For patients with CFT meningiomas, GKRS provides durable local tumor control rate and stabilizes or shrinks tumors in the vast majority of cases. In conjunction with surgical management, radiosurgery is part of a multimodal therapeutic strategy for this challenging meningioma subtype.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
01 February 2023