3D Volumetric Measurement of Neurofibromatosis Type 2-Associated Meningiomas: Association Between Tumor Location and Growth Rate

Objective: Treatment of meningiomas in neurofibromatosis type II (NF2) patients is challenging because the natural history of these tumors is unclear. More insight in tumor growth and factors predicting growth may contribute to a better clinical management. In this study, growth characteristics of supratentorial NF-related meningiomas were examined and the association between tumor growth rate and location was evaluated.

Methods: In all NF2 patients followed up at the VU University Medical Center, who underwent a minimum of 3 consecutive scans, tumor volumes were assessed by using 3D volumetric measurement (Brainlab, Feldkirchen, Germany). Growth patterns were visually analyzed. To assess the association between tumor growth rate and tumor location, the meningiomas were divided in 3 groups on the basis of their location: skull base, convexity, and "other." Univariable and multivariable logistic regression models were built.

Results: Twenty-one patients (13 females) with a mean (standard deviation) follow-up period of 5.55 (2.48) years and a total of 210 meningiomas were included in the analyses. Tumors followed different growth patterns and did not increase in size simultaneously within 1 patient. Skull base meningiomas had a significantly higher absolute growth rate compared with convexity (β = 0.91, 95% confidence interval [CI] 0.08-1.73) and "other" (β = 1.07, 95% CI 0.27-1.86) and a significantly higher relative growth rate on both linear and geometric growth rate compared with "other" (β = 90.73, 95% CI 5.50-175.95 and β = 18.63, 95% CI 2.94-34.31, respectively) on multivariable logistic regression.

Conclusion: Within a single patient, NF2-related meningiomas follow different growth patterns. Skull base meningiomas grow faster compared with other locations. Yearly magnetic resonance imaging scans and timely treatment of skull base meningiomas should be considered.