CT AND MR-IMAGING IN THE LOCAL STAGING OF PRIMARY MALIGNANT MUSCULOSKELETAL NEOPLASMS - REPORT OF THE RADIOLOGY DIAGNOSTIC ONCOLOGY GROUP

PURPOSE: To assess the relative accuracies of computed tomography (CT) and magnetic resonance (MR) imaging in the local staging of primary m alignant bone and soft-tissue tumors. MATERIALS AND METHODS: At four i nstitutions, 367 eligible patients (aged 6-89 years) with malignant bo ne or soft-tissue neoplasms in selected anatomic sites were enrolled. Patients underwent both CT and MR imaging within 4 weeks before surger y. In each patient, CT scans were interpreted independently by two rad iologists and MR images by two other radiologists at the enrolling ins titution. The CT and MR images were then interpreted together by two o f those radiologists and subsequently reread at the other institutions . Imaging and histopathologic findings were compared and were suppleme nted when needed with surgical findings. Receiver operating characteri stic curve analysis and descriptive statistical analysis were performe d. RESULTS: Cases were analyzable in 316 patients: 183 had primary bon e tumors; 133 had primary soft-tissue tumors. There was no statistical ly significant difference between CT and MR imaging in determining tum or involvement of muscle, bone, joints, or neurovascular structures. T he combined interpretation of CT and MR images did not statistically s ignificantly improve accuracy. Inter-reader variability was similar fo r both modalities. CONCLUSION: CT and MR imaging are equally accurate in the local staging of malignant bone and soft-tissue neoplasms in th e specific anatomic sites studied.