A single study by Platzek et al [17] in 2017 evaluated FDG-PET/MRI in sarcoma staging in 29 patients and compared results with conventional CT or MRI studies. Eight of the 29 patients had lung metastases, which were identified on both the FDG-PET/MRI and conventional imaging. However, the small sample size precludes application of this data to larger populations. The inherent decreased spatial resolution of MRI compared to CT raises doubts about the ability to identify small pulmonary metastases with FDG-PET/MRI as accurately as CT. MRI of the lungs relies heavily on the ability to minimize respiratory motion. Radiography Chest There is no relevant literature to support the use of chest radiography in the evaluation of pulmonary metastases in the initial staging of malignant or aggressive primary musculoskeletal tumors. Variant 2: Malignant or aggressive primary musculoskeletal tumor. Initial staging. Evaluation for extrapulmonary metastasis. The body regions covered in this clinical scenario are ankle, chest, shoulder, elbow, femur, foot, forearm, hand, humerus, knee, pelvis, tibia/fibula, and wrist. Bone Scan Whole Body Although historically Tc-99m bone scan has been used to detect bone metastasis, more recent studies have shown Tc-99m bone scan is inferior to FDG-PET/CT in the detection of bone metastases in general oncologic populations [23]. This conclusion has also been supported in patients with bone sarcoma. A study of 206 patients with stage IV osteosarcoma who underwent both Tc-99m bone scan and FDG-PET/CT calculated a 95% sensitivity and 98% accuracy for FDG-PET/CT versus 76% and 96%, respectively, for Tc-99m bone scan [24]. A smaller study of 64 pediatric patients with bone sarcoma also showed greater accuracy of FDG-PET/CT (84%) versus Tc-99m bone scan (70%) in detecting bone metastases during initial staging [22].
Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. A single study by Platzek et al [17] in 2017 evaluated FDG-PET/MRI in sarcoma staging in 29 patients and compared results with conventional CT or MRI studies. Eight of the 29 patients had lung metastases, which were identified on both the FDG-PET/MRI and conventional imaging. However, the small sample size precludes application of this data to larger populations. The inherent decreased spatial resolution of MRI compared to CT raises doubts about the ability to identify small pulmonary metastases with FDG-PET/MRI as accurately as CT. MRI of the lungs relies heavily on the ability to minimize respiratory motion. Radiography Chest There is no relevant literature to support the use of chest radiography in the evaluation of pulmonary metastases in the initial staging of malignant or aggressive primary musculoskeletal tumors. Variant 2: Malignant or aggressive primary musculoskeletal tumor. Initial staging. Evaluation for extrapulmonary metastasis. The body regions covered in this clinical scenario are ankle, chest, shoulder, elbow, femur, foot, forearm, hand, humerus, knee, pelvis, tibia/fibula, and wrist. Bone Scan Whole Body Although historically Tc-99m bone scan has been used to detect bone metastasis, more recent studies have shown Tc-99m bone scan is inferior to FDG-PET/CT in the detection of bone metastases in general oncologic populations [23]. This conclusion has also been supported in patients with bone sarcoma. A study of 206 patients with stage IV osteosarcoma who underwent both Tc-99m bone scan and FDG-PET/CT calculated a 95% sensitivity and 98% accuracy for FDG-PET/CT versus 76% and 96%, respectively, for Tc-99m bone scan [24]. A smaller study of 64 pediatric patients with bone sarcoma also showed greater accuracy of FDG-PET/CT (84%) versus Tc-99m bone scan (70%) in detecting bone metastases during initial staging [22].