A small study in patients with Ewing sarcoma showed more bone lesions were more accurately identified on MRI whole body when compared with FDG-PET/CT [35]. There are mixed conclusions when comparing FDG-PET/CT versus MRI whole body in detecting osseous metastases in general oncology populations [32-34]. MRI whole body is more sensitive than Tc-99m bone scan for detecting osseous metastasis in a variety of tumors known to metastasize to bone. Sensitivity was also higher specifically in patients with Ewing sarcoma [29]. Radiography Area of Interest Radiographs could be used to evaluate an area of interest identified clinically or from another imaging modality. There is no relevant literature to support the use of radiography at an area of interest in the initial staging for extrapulmonary metastasis of malignant or aggressive musculoskeletal tumors. US Area of Interest There is no relevant literature to support the use of ultrasound (US) area of interest in the initial staging for extrapulmonary metastasis of malignant or aggressive musculoskeletal tumors. US could be used to evaluate an area of interest identified clinically or from another imaging modality. US is more useful to evaluate superficial soft tissue masses as opposed to bone lesions, which are usually occult if there is no cortical breakthrough. Variant 3: Malignant or aggressive primary musculoskeletal tumor with no suspected or known recurrence. Surveillance for pulmonary metastasis. Pulmonary metastases account for the majority of distant metastatic disease in patients with primary extremity sarcoma as a whole. Risk of pulmonary metastasis varies with tumor histology and grade. Although patients with high-grade soft tissue sarcomas develop lung metastasis at a rate of ~60%, those with low-grade sarcomas have lung metastasis rates <10% [45,46]. Therefore, guidance regarding modality for lung screening often differ between low-risk and high-risk patients.
Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. A small study in patients with Ewing sarcoma showed more bone lesions were more accurately identified on MRI whole body when compared with FDG-PET/CT [35]. There are mixed conclusions when comparing FDG-PET/CT versus MRI whole body in detecting osseous metastases in general oncology populations [32-34]. MRI whole body is more sensitive than Tc-99m bone scan for detecting osseous metastasis in a variety of tumors known to metastasize to bone. Sensitivity was also higher specifically in patients with Ewing sarcoma [29]. Radiography Area of Interest Radiographs could be used to evaluate an area of interest identified clinically or from another imaging modality. There is no relevant literature to support the use of radiography at an area of interest in the initial staging for extrapulmonary metastasis of malignant or aggressive musculoskeletal tumors. US Area of Interest There is no relevant literature to support the use of ultrasound (US) area of interest in the initial staging for extrapulmonary metastasis of malignant or aggressive musculoskeletal tumors. US could be used to evaluate an area of interest identified clinically or from another imaging modality. US is more useful to evaluate superficial soft tissue masses as opposed to bone lesions, which are usually occult if there is no cortical breakthrough. Variant 3: Malignant or aggressive primary musculoskeletal tumor with no suspected or known recurrence. Surveillance for pulmonary metastasis. Pulmonary metastases account for the majority of distant metastatic disease in patients with primary extremity sarcoma as a whole. Risk of pulmonary metastasis varies with tumor histology and grade. Although patients with high-grade soft tissue sarcomas develop lung metastasis at a rate of ~60%, those with low-grade sarcomas have lung metastasis rates <10% [45,46]. Therefore, guidance regarding modality for lung screening often differ between low-risk and high-risk patients.