Tumor location and morphological MRI features in relation to combined 1p/22q deletion in meningioma

Background Combined chromosomal 1p/22q deletion is associated with aggressive tumor biology and an increased risk of recurrence in meningiomas. Since C-IMPACT-NOW Update 8, this molecular alteration has gained relevance in the stratification of WHO grade 2 tumors. However, reliable preoperative predictors of combined 1p/22q deletion remain limited. The present study aimed to identify clinical and radiological predictors of combined 1p/22q deletion in meningiomas. Methods In this retrospective single-center study, 197 patients with histopathologically confirmed meningiomas and available chromosomal status were analyzed. Preoperative MRI-based tumor characteristics, including tumor volume, surface area, roundness, flatness, and length of dural attachment, were assessed on gadolinium-enhanced T1-weighted MRI. Tumor volumetry was performed using the SmartBrush tool within the BrainLAB software (BrainLAB, Munich, Germany) via a semi-automatic segmentation flow. Surface area, roundness and flatness were derived using the open-source software 3D Slicer. Optimal cut-off values were determined using receiver operating characteristic (ROC) curve analysis with the Youden index. Variables were evaluated using uni- and multivariable analyses. Anatomical subgroup analysis was performed in non–skull base (NSB) meningiomas. Results In the overall cohort, NSB location was independently associated with combined 1p/22q deletion (OR 3.267, 95% CI 1.012–10.545; p = 0.048). In the NSB subgroup ( n = 102), tumor volume ( p = 0.027), tumor surface area ( p = 0.020), and length of dural attachment ( p = 0.042) were significantly associated with combined 1p/22q deletion in univariate analyses. Conclusion NSB meningiomas are independently associated with combined 1p/22q deletion. Quantitative and anatomically interpretable MRI-based tumor characteristics, particularly in NSB tumors, may provide supplementary information for preoperative risk stratification. These characteristics may contribute to decision-making process and identifying those necessitating surgery due to potential aggressive biological behavior.