Clinical utility of ¹⁸F-FDG PET/CT imaging in patients with pulmonary artery sarcoma

Pulmonary artery sarcoma (PAS) is a rare and fatal malignancy. Due to the lack of specific clinical and radiological features, PAS is always misdiagnosed as pulmonary thromboembolism (PTE). This study aimed to investigate ¹⁸F-FDG PET/CT in distinguishing PAS from PTE, and analyze its correlation with clinical and radiological findings and outcome of PAS.

Clinical, contrast-enhanced CT, and ¹⁸F-FDG PET/CT characteristics of 14 patients with PAS and 33 patients with PTE were retrospectively reviewed. The correlation between PET/CT metabolic parameters vs. clinical and CT findings was investigated in patients with PAS. The overall survival (OS) was analyzed in PAS patients.

The SUVmax of PAS (median: 8.0, range 3.0-17.2) was significantly higher than PTE (1.8[0.8-3.7]) (P < 0.001), and at a cutoff value of 2.9, the sensitivity and specificity were 100.0% and 93.9%, respectively. Compared with PTE, PAS more frequently occurred in younger population (P = 0.011), involved pulmonary trunk (P < 0.001), and displayed higher enhanced CT (P < 0.001) and ΔCT (enhanced CT compared to non-enhanced CT) (P < 0.001) values. SUVmax of PAS was associated with tumor staging (P = 0.022) and enhanced CT (P = 0.013) and ΔCT (P = 0.005) values. The median OS of PAS patients was 10.5 months, and 12-month and 24-month OS rates were 58.0% and 12.0%, respectively. Only D-dimer level (P = 0.038) and tumor staging (P = 0.019) were associated with OS.

Most PAS displayed high glucometabolism, and SUVmax of ¹⁸F-FDG PET/CT was useful in distinguishing PAS from PTE.