Synovial sarcoma of the soft tissues - Prognostic significance of imaging features

Objective: This study assessed the prognostic value of computed tomography (CT) and magnetic resonance (MR) imaging features in synovial sarcoma of the soft tissues. Methods: CT and MR imaging studies were performed in 30 patients with pathologically confirmed synovial sarcoma of the soft tissues. CT and MR imaging findings obtained by 2 radiologists with agreement by consensus were compared for histopathologic features including tumor grade. Univariate analyses were conducted to clarify the impact of imaging findings on overall survival with a medium duration of 32 months. Multivariate analysis was estimated using a Cox proportional hazards model with the relative risk of each variable. Results: Statistically significant imaging findings favoring a diagnosis of high-grade tumor included proximal distribution (P < 0.01), large tumor size (>10 cm, P < 0.05), the absence of calcification (P < 0.05), tumor possessing cyst (P < 0.01), the presence of hemorrhage (P < 0.05), and the presence of triple signal pattern (P < 0.05). Univariate analysis showed that proximal distribution (P < 0.05), tumor size larger than 5 cm (P < 0.01), the absence of calcification (P < 0.01), the presence of hemorrhage (P < 0.05), and the presence of triple signal pattern (P < 0.05) had a significant association with the disease-free survival (DFS). Multiple logistic regression models revealed that tumor size larger than 10 cm had a significant impact on the DFS with relative risk of 18.8 (P < 0.05). Conclusion: CT and MR imaging studies allow prognosis prediction in patients with synovial sarcoma of the soft tissues.