Multimodal Approach to Detect Osseous Involvement in Meningioma: Additional Value of 18F-Fluoride PET/CT for Conventional Imaging

Purpose: To compare the diagnostic performance of fluorine 18 (F-18) fluoride positron emission tomography (PET)/computed tomography (CT) with that of conventional imaging (CT and magnetic resonance [MR] imaging) in evaluating the osseous involvement in meningioma. Materials and Methods: The study was approved by the ethics committee and institutional review board and was conducted according to the Declarations of Helsinki and Tokyo. Written informed consent was obtained from all patients. A retrospective comparative study between F-18-fluoride PET/CT and conventional imaging was conducted to detect osseous involvement in patients with a verified diagnosis of meningioma. Osseous involvement was verified by using definitive surgery (including drilling or careful sampling of the skull in all patients). The diagnostic performance, determined by calculating the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, was assessed. Results: Data sets from a total of 78 patients with proven meningioma were compared. Osseous involvement was histopathologically confirmed in 25 patients (32%). The sensitivity, specificity, PPV, NPV, and accuracy were 92.0%, 86.8%, 76.7%, 95.8%, and 88.5% for F-18-fluoride PET/CT and 64.0%, 83.0%, 64.0%, 83.0%, and 76.9% for conventional imaging, respectively. The receiver operating characteristic (ROC) analysis revealed that the area under the ROC curve (A(z)) value of F-18-fluoride PET/CT was significantly greater than that of conventional imaging (0.965 +/- 0.02 [standard error] vs 0.703 +/- 0.066 [standard error], P < .0001). Conclusion: An approach using F-18-fluoride PET/CT improves preoperative detection of osseous involvement. In those without abnormal F-18-fluoride uptake within the skull, the patient may proceed directly to conventional surgery. However, a positive finding of osseous involvement at F-18-fluoride PET/CT should prompt confirmation by drilling or sampling of bone. (C) RSNA, 2014