Preoperative Tumor and Edema Volumes Strongly Correlate with Postoperative Diffusion Changes in Meningioma Surgery

Introduction: Meningiomas are common intracranial tumors often treated with surgery, but predicting postoperative outcomes remains challenging. Postoperative DWI changes are essential determinants of postoperative neurological outcomes. Yet, predictors of postoperative DWI changes are largely unknown. We investigated whether preoperative tumor and edema volumes can predict postoperative ischemic changes.

Methods: Retrospective analysis was conducted on 152 patients who underwent meningioma resection in single center between 2008 to 2023. We collected clinical, radiological, operative, and histopathological data. Tumor volume was measured on postcontrast T1W, and peritumoral edema was measured on FLAIR images correlated with postoperative DWI volume using volumetric measurements on 3D SlicerTM. Statistical analyses were performed using SPSS version 23.0, with Spearman's rho test used to assess correlations between imaging parameters and postoperative DWI volume.

Results: The study included 152 patients with a mean age of 52.2±13.1 years (67.1% female). Tumor grades were 73.7% grade I, 23.7% grade II, and 2.6% grade III. The median preoperative tumor volume was 23.1 cm³ (IQR 9.3–48.4 cm³), and the median FLAIR volume was 3.5 cm³ (IQR 0.0–28.4 cm³). Total resection was achieved in 70.4% of patients (Simpson grade 1,2,3), with a mean extent of resection (EOR) of 94%. Preoperative deficits were present in 45.4% of patients. New deficits, including sensory and motor impairments, occurred in 6.6% of cases. The median postoperative DWI volume was 1.5 cm³ (IQR 0.0–5.3 cm³). Significant correlations were found between preoperative tumor volume and postoperative DWI volume (Spearman's rho=0.393, p< 0.001), as well as between preoperative FLAIR volume and postoperative DWI volume (Spearman's rho=0.446, p< 0.001).

Conclusion : Preoperative tumor and FLAIR volumes strongly correlate with postoperative DWI volume in meningiomas. Our findings suggest that preoperative imaging can help guide surgical outcomes and optimize patient management. Volumetric analyses may refine treatment timing and strategies, ultimately enhancing patient care.