Diagnostic usefulness of 18F-FDG PET/CT in the differentiation of pulmonary artery sarcoma and pulmonary embolism

The purpose of this study was to evaluate the usefulness of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in differentiating pulmonary artery sarcoma from pulmonary embolism. We evaluated three patients with pulmonary artery sarcoma and 10 patients with proximal pulmonary embolism (6 men and 7 women, ranging in age from 35 to 94 years). All the patients had evidence of perfusion defects in their proximal pulmonary arteries on contrast-enhanced computed tomography (CT) scans performed prior to PET/CT. The maximum standardized uptake value (SUVmax) of FDG uptake in all the lesions was measured using PET/CT. The location of lesions, background uptake or thrombi in the legs were evaluated in both groups as basic characteristics. The mean SUVmax of the pulmonary artery sarcomas (7.63 +/- A 2.21, n = 3) and the pulmonary embolisms (2.31 +/- A 0.41, n = 10) were significantly different (P < 0.05). The mean times between the initial contrast-enhanced CT scan and PET/CT scan were similar in both groups (P = 0.7804). The differences in the locations in lesions between the three groups (right, left and bilateral) or background uptakes were not significant. FDG PET/CT could distinguish pulmonary artery sarcoma from pulmonary embolism based on the SUVmax value.