Risk Assessment Based on FDG-PET Imaging in Patients with Synovial Sarcoma

Synovial sarcoma generally is associated with poor prognosis. With recent advances in molecular biology, it has become apparent not all synovial sarcomas share the same tumor biology. ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) is useful for risk assessment in several types of sarcomas. We therefore assessed the clinical value of ¹⁸F-FDG-PET-derived maximum standard uptake value (SUV_max) for predicting survival in patients with synovial sarcoma. ¹⁸F-FDG-PET was performed in 44 patients with synovial sarcoma before therapy and resection. SUV_max was calculated for each tumor and then evaluated for prognostic usefulness along with metastasis at presentation, tumor grade, histopathologic subtype, age, gender, postsurgical margins, anatomic location, and tumor size for overall survival and progression-free survival. SUV_max ranged from 1.2 to 13.0 (median, 4.35). Pretherapy tumor SUV_max predicted overall survival and progression-free survival. Patients presenting with a SUV_max greater than 4.35 had a decreased disease-free survival and were therefore at high risk for having local recurrences and metastatic disease.