Growth Patterns of Intracavernous Meningiomas after Surgical

Introduction: Meningiomas involving the cavernous sinus pose a unique challenge to surgeons. Often impossible to resect without unacceptable morbidity, optimal management strategy of the residual tumor remains controversial. While radiosurgery may offer benefit in some cases, it remains unclear which tumors would benefit from early radiation vs a conservative approach. In an effort to better understand the natural history of these lesions, especially in the postoperative period, we reviewed the radiographic follow-up of residual intracavernous WHO grade I meningiomas to assess growth patterns after partial surgical resection.

Methods: A retrospective review of all patients who underwent surgery for meningiomas of the base of the skull was performed to identify patients with WHO grade I meningiomas involving the cavernous sinus with identifiable residual tumor on immediate postoperative MRI. Follow-up MRIs were then reviewed to determine growth pattern of the intracavernous portion of the tumors.

Results: Between 2012 and 2016, nineteen patients who underwent surgery for partial resection of meningiomas involving the cavernous sinus were identified who had follow-up imaging at a minimum of 12 months postoperatively. 79% of patients were female (n = 15). Average length of follow-up was 25.6 months (range: 13–40). Absolute growth measured on coronal or axial T1-gadolinium-enhanced MRI ranged between 0 and 12.5 mm in the diameter of maximal growth. Overall rates of growth ranged from 0 to 7.3 mm/year with an average growth rate of 1.8 mm/year. 31.5% (n = 6) of patients exhibited no growth during the follow-up period and 68.4% of patients (n = 13) exhibited growth rates of 1 mm or less per year. By comparison, 68.4% of patients (n = 13) had definitive growth in their lesions at follow-up and 21% of patients (n = 4) exhibited growth of more than 5 mm per year.

Conclusion: While the optimal management strategy for residual intracavernous meningiomas remains uncertain, here we provide evidence that the natural history of these residual lesions is variable, and there may be a role for upfront radiosurgery/radiation therapy. Larger, multicenter studies are warranted to better determine predictive factors of growth and the true natural history of these complex and challenging tumors.

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