Can Preoperative Imaging Predict Tumor Involvement of the Anterior Clinoid in Clinoid Region Meningiomas?

Objective: We investigated whether preoperative imaging could predict tumor involvement of the anterior clinoid, and therefore tailor the degree of bony removal, in clinoid region meningiomas. Design: Included were patients having undergone resection of a clinoid region meningioma at our institution between 2001 and 2011 in which an anterior clinoidectomy was performed with subsequent pathologically confirmed presence or absence of tumor in the clinoid process on decalcified specimens. Two neuroradiologists, blinded to pathology results, independently reviewed preoperative imaging and stated whether or not they anticipated the anterior clinoid to be involved by tumor. Interobserver agreement and the ability to predict tumor involvement of the clinoid were then analyzed. Results: In this study, 62 patients were included. Interobserver agreement was 100%. Sensitivity and specificity of preoperative imaging to predict tumor involvement was 89 and 52%, respectively, with positive and negative likelihood ratios of 1.85 and 0.20. Positive and negative predictive values were 73 and 76%, respectively. Conclusion: Preoperative imaging of clinoid region meningiomas can accurately predict the presence or absence of tumor involvement of the anterior clinoid in only approximately 75% of cases. We recommend clinoidectomy for all clinoid region meningiomas in light of the fact that a quarter of patients with radiographically negative clinoids will have tumor present on pathologic analysis.