There is no relevant literature to specifically 6 Malignant or Aggressive Primary Musculoskeletal Tumor support the use of fluoride PET/CT in the initial staging for extrapulmonary metastasis of malignant or aggressive musculoskeletal tumors. Specifically, extraosseous extrapulmonary metastases will usually be occult on fluoride PET/CT whole body scans. MRI Whole Body Without and With IV Contrast There is no relevant literature to support the use of MRI whole body without and with IV contrast in the initial staging for extrapulmonary metastasis of malignant or aggressive musculoskeletal tumors. However, the addition of IV contrast can be helpful for assessing soft tissue masses and therefore could be beneficial in this setting. MRI Whole Body Without IV Contrast The ability of MRI to characterize soft tissue and bone marrow make it ideal for identifying extrapulmonary metastases. MRI is particularly useful in identifying and accurately characterizing bone marrow abnormalities as metastases versus nonmalignant processes. Hematopoietic marrow, or red marrow, is a frequently encountered nonmalignant marrow abnormality that can be mistaken for a metastasis on other modalities, particularly on PET imaging, when there is relatively increased metabolic activity. Hematopoietic marrow is abundant in the pediatric and young adult populations making it problematic for the staging of bone sarcomas in these populations. Multiple medications and other systemic illnesses can activate hematopoietic marrow in the adult population. Specific to myxoid liposarcoma, a sarcoma subtype known to metastasize preferentially to extrapulmonary locations, multiple studies have found MRI to be more accurate than FDG-PET, FDG-PET/CT, CT, radiography, and bone scintigraphy imaging to detect extrapulmonary metastases [40-44].
Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. There is no relevant literature to specifically 6 Malignant or Aggressive Primary Musculoskeletal Tumor support the use of fluoride PET/CT in the initial staging for extrapulmonary metastasis of malignant or aggressive musculoskeletal tumors. Specifically, extraosseous extrapulmonary metastases will usually be occult on fluoride PET/CT whole body scans. MRI Whole Body Without and With IV Contrast There is no relevant literature to support the use of MRI whole body without and with IV contrast in the initial staging for extrapulmonary metastasis of malignant or aggressive musculoskeletal tumors. However, the addition of IV contrast can be helpful for assessing soft tissue masses and therefore could be beneficial in this setting. MRI Whole Body Without IV Contrast The ability of MRI to characterize soft tissue and bone marrow make it ideal for identifying extrapulmonary metastases. MRI is particularly useful in identifying and accurately characterizing bone marrow abnormalities as metastases versus nonmalignant processes. Hematopoietic marrow, or red marrow, is a frequently encountered nonmalignant marrow abnormality that can be mistaken for a metastasis on other modalities, particularly on PET imaging, when there is relatively increased metabolic activity. Hematopoietic marrow is abundant in the pediatric and young adult populations making it problematic for the staging of bone sarcomas in these populations. Multiple medications and other systemic illnesses can activate hematopoietic marrow in the adult population. Specific to myxoid liposarcoma, a sarcoma subtype known to metastasize preferentially to extrapulmonary locations, multiple studies have found MRI to be more accurate than FDG-PET, FDG-PET/CT, CT, radiography, and bone scintigraphy imaging to detect extrapulmonary metastases [40-44].