Advanced CT techniques, such as dual- energy CT, have shown promise in differentiating malignant from nonmalignant tumors, although further research in this area is needed [24]. MRI is generally considered the preferred imaging modality for staging of bone tumors. Some cases may benefit from both MRI and CT because these modalities provide complementary information regarding soft-tissue (often better evaluated on MRI) and matrix mineralization (often better evaluated on CT). There is no relevant literature regarding the specific use of CT with IV contrast or CT without and with IV contrast in the evaluation of suspected primary bone tumor with radiographs indeterminate for malignancy. However, if contrast is given, CT without and with IV contrast is preferred because it allows differentiation of areas of contrast enhancement from areas of osseous matrix production. FDG-PET/CT Whole Body FDG-PET has proven useful for further characterizing indeterminate bone tumors identified on radiographs. PET information can be co-registered with CT or MRI, taking advantage of the inherent benefits of these modalities. A number of studies have shown FDG-PET and FDG-PET/CT to be a valuable adjunct to conventional imaging in the diagnosis, staging, restaging, and surveillance of primary bone tumors [25-31]. Shin et al [32] evaluated the efficacy of FDG-PET/CT in differentiating benign from malignant pathologic fractures in a series of 34 patients. With a standardized uptake value max cut-off set at 4.7, they found the sensitivity, specificity, and diagnostic accuracy of FDG-PET/CT to be 89.5%, 86.7%, and 88.2%, respectively. However, it was noted that there may be significant overlap in the metabolic activity of benign and malignant lesions, such as those containing myxoid or necrotic components with inherent low metabolic activity.
Primary Bone Tumors. Advanced CT techniques, such as dual- energy CT, have shown promise in differentiating malignant from nonmalignant tumors, although further research in this area is needed [24]. MRI is generally considered the preferred imaging modality for staging of bone tumors. Some cases may benefit from both MRI and CT because these modalities provide complementary information regarding soft-tissue (often better evaluated on MRI) and matrix mineralization (often better evaluated on CT). There is no relevant literature regarding the specific use of CT with IV contrast or CT without and with IV contrast in the evaluation of suspected primary bone tumor with radiographs indeterminate for malignancy. However, if contrast is given, CT without and with IV contrast is preferred because it allows differentiation of areas of contrast enhancement from areas of osseous matrix production. FDG-PET/CT Whole Body FDG-PET has proven useful for further characterizing indeterminate bone tumors identified on radiographs. PET information can be co-registered with CT or MRI, taking advantage of the inherent benefits of these modalities. A number of studies have shown FDG-PET and FDG-PET/CT to be a valuable adjunct to conventional imaging in the diagnosis, staging, restaging, and surveillance of primary bone tumors [25-31]. Shin et al [32] evaluated the efficacy of FDG-PET/CT in differentiating benign from malignant pathologic fractures in a series of 34 patients. With a standardized uptake value max cut-off set at 4.7, they found the sensitivity, specificity, and diagnostic accuracy of FDG-PET/CT to be 89.5%, 86.7%, and 88.2%, respectively. However, it was noted that there may be significant overlap in the metabolic activity of benign and malignant lesions, such as those containing myxoid or necrotic components with inherent low metabolic activity.