Is FDG-PET/CT Useful for Diagnosing Pulmonary Metastasis in Patients with Soft Tissue Sarcoma?

` Background/Aim: In patients with soft tissue sarcoma (STS), distinguishing small metastatic pulmonary nodules from benign ones remains difficult. This study aimed to determine the accuracy of F-18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in detecting pulmonary metastasis and identify factors affecting sensitivity with STS. Materials and Methods: The clinical records and chest CT and FDG-PET/CT scans of 102 patients with STS were reviewed to determine the presence of pulmonary nodules. Results: A significant relationship was observed between nodule size and maximum standardized uptake value (SUVmax). For nodules smaller than 5 mm, only 10 out of 76 metastatic pulmonary nodules exhibited FDG- accumulation, showing a weak correlation between nodule size and SUVmax. Conclusion: The role of FDG-PET/CT in differentiating metastatic from benign pulmonary nodules was unsatisfactory, especially for small nodules. Careful followup using CT scan may still be appropriate for diagnosing pulmonary nodules smaller than 5 mm.