RESUMEN
OBJECTIVE: The authors' aim was to assess the velocity and pattern of growth of meningiomas and to correlate the kinetics of tumor growth with their previously reported two-item radiological risk stratification and CNS WHO grade (5th edition, 2021). METHODS: The authors performed a serial volumetric analysis of meningiomas diagnosed radiologically at their institution between 2003 and 2015. The primary endpoint was velocity of diametric expansion (VDE), which represents the slope of the linear regression of the mean tumor diameter against time. For the secondary analysis, they categorized the growth patterns as linear or exponential by fitting time-volume curves to a linear and exponential function. Three radiological risk categories based on T2-weighted iso/hyperintensity and absence of calcifications were compared: low risk (T2-weighted hypointense), intermediate-risk (T2-weighted iso/hyperintense with calcifications), and high-risk (T2-weighted iso/hyperintense without calcifications) tumors. RESULTS: For the entire cohort of 240 meningiomas, the median (IQR) VDE was 0.33 (0.00-0.71) mm/year. Distribution of VDE differed significantly among radiological risk categories (0.49 vs 0.35 vs 0.05 mm/year, p < 0.001). High-risk and intermediate-risk tumors more frequently tended to grow exponentially compared to low-risk tumors (43.8% vs 37.0% vs 8.3%, p = 0.067). The authors found no correlation of growth velocity with CNS WHO grade in their cohort (1.30 mm/year for CNS WHO grade 1 vs 4.01 mm/year for CNS WHO grade 2, p = 0.185). CONCLUSIONS: A radiological risk assessment using two parameters-T2-weighted signal iso/hyperintensity and absence of calcifications-allows estimation of growth velocity and characteristics of untreated intracranial meningiomas. Only high-risk tumors exhibit the potential for rapid growth. However, rapid tumor growth does not indicate a higher CNS WHO grade per se.
RESUMEN
OBJECTIVE: The management of asymptomatic intracranial meningiomas is controversial. Through the assessment of growth predictors, the authors aimed to create the basis for practicable clinical pathways for the management of these tumors. METHODS: The authors volumetrically analyzed meningiomas radiologically diagnosed at their institution between 2003 and 2015. The primary endpoint was growth of tumor volume. The authors used significant variables from the multivariable regression model to construct a decision tree based on the exhaustive Chi-Square Automatic Interaction Detection (CHAID) algorithm. RESULTS: Of 240 meningiomas, 159 (66.3%) demonstrated growth during a mean observation period of 46.9 months. On multivariable logistic regression analysis, older age (OR 0.979 [95% CI 0.958-1.000], p = 0.048) and presence of calcification (OR 0.442 [95% CI 0.224-0.872], p = 0.019) had a negative predictive value for tumor growth, while T2-signal iso-/hyperintensity (OR 4.415 [95% CI 2.056-9.479], p < 0.001) had a positive predictive value. A decision tree model yielded three growth risk groups based on T2 signal intensity and presence of calcifications. The median tumor volume doubling time (Td) was 185.7 months in the low-risk, 100.1 months in the intermediate-risk, and 51.7 months in the high-risk group (p < 0.001). Whereas 0% of meningiomas in the low- and intermediate-risk groups had a Td of ≤ 12 months, the percentage was 8.9% in the high-risk group (p = 0.021). CONCLUSIONS: Most meningiomas demonstrated growth during follow-up. The absence of calcifications and iso-/hyperintensity on T2-weighted imaging offer a practical way of stratifying meningiomas as low, intermediate, or high risk. Small tumors in the low- or intermediate-risk categories can be monitored with longer follow-up intervals.