Tumor Doubling Time as Preoperative Predictor of Malignancy and Recurrence in Newly Diagnosed Meningioma

Objective: Most meningiomas are benign and the indications for surgery are determined by size and symptoms, but some are malignant and have a high recurrence rate. Currently, no preoperative prognostic factors have been established. The purpose of this study was to investigate whether Tumor doubling time (Td) is useful in predicting tumor prognosis. Methods Patients who underwent surgery for newly diagnosed meningioma at our hospital between 2007 and 2021 with preoperative magnetic resonance (MR) imaging evaluation over a period of six months were included in this study. We calculated the Td from the preoperative MR images and examined the correlation between Td and WHO grade, MIB-1 SI and other conditions. Results A total of 269 newly diagnosed meningiomas were operated in the period, of which 62 met inclusion criteria. The median Td was 1082 days (54-8579 days) and MIB-1 SI was 2.45% (0.7–14.6%). Td and MIB-1 SI had a negative correlation (r=-0.319, p = 0.0122). MIB-1 SI was higher in patients with Td  = 3 (p = 0.005), and the incidence of high WHO grade (grade2) was higher in patients with Td  = 1 (p = 0.014). Conclusions Meningiomas with Td of less than 3 years had significantly higher MIB-1 SI, and tumors with Td of less than 1 year had higher likelihood of malignancy. Therefore, early treatment should be considered for the patients with short Td meningioma even if asymptomatic and further consideration could be given to radical resection at the time of surgery.