Other studies have differing conclusions. A large multicenter retrospective study by Gamboa et al [45] comparing lung surveillance in 909 patients with extremity, truncal, or retroperitoneal high-grade soft tissue sarcomas found the 5-year survival rate was noninferior for patients followed with chest radiography versus CT chest (71% versus 60%). This study also found there was no difference in the rate or type of intervention for these lung metastases when detected. Selection bias was a limitation of both of these retrospective studies because the rationale of which modality used to screen was not known or reported. Additionally, the Gamboa et al [45] study included 151 patients with retroperitoneal sarcoma, which has a high rate of local recurrence; this group was overrepresented in the CT imaging group, which had the worse survival rate. A prospective randomized trial of 500 patients with resected extremity bone and soft tissue sarcomas without baseline metastases showed noninferiority of chest radiography compared with CT chest with similar overall survival (56% versus 53% respectively) and recurrence-free survival (59% versus 54% respectively) when used for lung surveillance [53,54]. FDG-PET/CT Whole Body Although FDG-PET/CT is not as sensitive for detecting pulmonary metastases as CT chest imaging, it has been shown to be more specific and therefore may be useful as a problem-solving tool when an indeterminate pulmonary nodule is detected on diagnostic chest CT. A study comparing staging and follow-up imaging studies in 41 children with primary bone sarcomas showed greater sensitivity of CT chest (93%) versus FDG-PET/CT (80%) in detecting pulmonary metastases (although specificity was higher with FDG-PET/CT at 96% compared with 87% for CT chest). Of the false-negative FDG-PET/CT results in that study, half were pulmonary nodules <10 mm [15].
Malignant or Aggressive Primary Musculoskeletal Tumor Staging And Surveillance PCAs. Other studies have differing conclusions. A large multicenter retrospective study by Gamboa et al [45] comparing lung surveillance in 909 patients with extremity, truncal, or retroperitoneal high-grade soft tissue sarcomas found the 5-year survival rate was noninferior for patients followed with chest radiography versus CT chest (71% versus 60%). This study also found there was no difference in the rate or type of intervention for these lung metastases when detected. Selection bias was a limitation of both of these retrospective studies because the rationale of which modality used to screen was not known or reported. Additionally, the Gamboa et al [45] study included 151 patients with retroperitoneal sarcoma, which has a high rate of local recurrence; this group was overrepresented in the CT imaging group, which had the worse survival rate. A prospective randomized trial of 500 patients with resected extremity bone and soft tissue sarcomas without baseline metastases showed noninferiority of chest radiography compared with CT chest with similar overall survival (56% versus 53% respectively) and recurrence-free survival (59% versus 54% respectively) when used for lung surveillance [53,54]. FDG-PET/CT Whole Body Although FDG-PET/CT is not as sensitive for detecting pulmonary metastases as CT chest imaging, it has been shown to be more specific and therefore may be useful as a problem-solving tool when an indeterminate pulmonary nodule is detected on diagnostic chest CT. A study comparing staging and follow-up imaging studies in 41 children with primary bone sarcomas showed greater sensitivity of CT chest (93%) versus FDG-PET/CT (80%) in detecting pulmonary metastases (although specificity was higher with FDG-PET/CT at 96% compared with 87% for CT chest). Of the false-negative FDG-PET/CT results in that study, half were pulmonary nodules <10 mm [15].