MNGO-07PROGNOSTIC FACTORS ASSOCIATED WITH OUTCOME OF CONSERVATIVE MANAGEMENT OF INTRACRANIAL MENINGIOMAS; A THREE-DIMENSIONAL VOLUMETRIC STUDY

Abstract

BACKGROUND: Despite asymptomatic meningiomas are typically dealt with ‘wait and see’ policy, data to predict which meningioma patients will fail to respond to conservative management are lacking. METHODS: Between 2003 and 2012, 178 patients with 205 meningiomas were managed with clinical and radiographical follow up for two years or longer without any kind of therapeutic intervention. Data were analyzed according to age, sex, tumor location, symptoms, initial tumor diameter, calcification, MR imaging intensity, and edema.3-dimensional volumetric analysis was also conducted in 205 meningiomas. RESULTS: Among 205 meningiomas, 156 meningiomas (76%) were maintaining clinico-radiographic observation but 49 (24%) meningiomas eventually had treatment after two years or longer period of clinico-radiological observation. The median tumor volume in treated patient group was 4.64cc initially, and 7.62cc just prior to the treatment with a mean follow-up of 45.9 months. The median tumor volume in untreated patient group was 1.96cc initially and 2.77cc at the end of observation with a mean follow-up of 54.8 months. The annual tumor growth rate was 0.93cc/year in treated group, and 0.03cc/year in untreated group. Kaplan-Meier analysis and Cox proportional hazards regression with Binary logistic regression analysis revealed that tumor growth rate not less than 1cc/yr (hazard ratio [HR] 9,705, 95% CI 3.91–24.73, p < 0.001) and the absence of calcification (HR 3.015, 95% CI 1.32-6.88, p < 0.0009) were factors associated with cessation of observation. CONCLUSIONS: Although the authors could obtain variable results depending on the measurement method, the data demonstrate that meningiomas characterized by volumetric tumor growth not less than 1cc/year and absence of calcification have high likelihood of undergoing treatment ultimately.