Diagnostic accuracy of computed tomography and magnetic resonance imaging compared to surgical exploration for anterior skull base and medial orbital wall infiltration in advanced sinonasal tumors

BACKGROUND: Knowledge of medial orbital wall (MOW) and anterior skull base (ASB) infiltration is of uttermost importance for staging and therapy planning of advanced sinonasal tumors. METHODS: We assessed the diagnostic performance of preoperative computed tomography (CT) and magnetic resonance imaging (MRI) for MOW and ASB infiltration compared to intraoperative exploration. RESULTS: Both CT and MRI yielded higher diagnostic accuracy for MOW infiltration (Reader 1: 83.6% CT; 89.0% MRI, Reader 2: 91.8% CT, 93.2% MRI) than for ASB infiltration (Reader 1: 82.2% CT, 82.2% MRI, Reader 2: 67.7% CT, 67.7% MRI). Both modalities were equal to the gold standard, except for ASB assessment by Reader 2 with MRI. A postoperative change of T classification is common (Reader 1: 28.8%, Reader 2: 31.5%). CONCLUSIONS: CT and MRI are accurate methods for the assessment of MOW infiltration. ASB assessment is challenging and false-positive and false-negative findings are common with both methods, emphasizing the need for intraoperative exploration.