Treatment-induced pathologic necrosis is an independent predictor of both local recurrence and overall survival in patients who receive neoadjuvant therapy for high-grade extremity soft tissue sarcomas. A complete pathologic response (> or = 95% pathologic necrosis) correlated with a significantly lower rate of local recurrence and improved overall survival.

Ifosfamide-based chemotherapy was associated with an improved DSS in adult patients with high-risk, primary, extremity, synovial sarcoma and should be considered in the treatment of such patients.

In patients with large, high-grade, primary extremity liposarcoma; DOX is not associated with improved DSS and IF is associated with an improved DSS. Treatment with IF should be considered in patients with high-risk primary extremity liposarcoma.

Purpose: Change in tumor size as classified by Response Evaluation Criteria in Solid Tumors poorly correlates with histopathologic response to neoadjuvant therapy in patients with softtissue sarcomas. The aim of this study was to prospectively evaluate whether positron emission tomography with 18 F-fluorodeoxyglucose (FDG-PET) allows for a more accurate evaluation of histopathologic response. Experimental Design: From January 2005 to January 2007, 42 patients with resectable biopsy-proven high-grade soft-tissue sarcoma underwent a FDG-PET/computed tomography scan before and after neoadjuvant treatment. Relative changes in tumor FDG uptake and size from the baseline to the follow-up scan were calculated, and their accuracy for assessment of histopathologic response was compared by receiver operating characteristic curve analysis. Histopathologic response was defined as z95% tumor necrosis. Results: In histopathologic responders (n = 8; 19%), reduction in tumor FDG uptake was significantly greater than in nonresponders (P < 0.001), whereas no significant differences were found for tumor size (P = 0.24). The area under the receiver operating characteristic curve for metabolic changes was 0.93, but only 0.60 for size changes (P = 0.004). Using a 60% decrease in tumor FDG uptake as a threshold resulted in a sensitivity of 100% and a specificity of 71% for assessment of histopathologic response, whereas Response Evaluation Criteria in Solid Tumors showed a sensitivity of 25% and a specificity of 100%. Conclusion: Quantitative FDG-PET was significantly more accurate than size-based criteria at assessing histopathologic response to neoadjuvant therapy. FDG-PETshould be considered as a modality to monitor treatment response in patients with high-grade soft-tissue sarcoma.

Can Benign Masses Be Differentiated from Malignant Ones?' A blinded, retrospective review of 83 soft-tissue masses (49 benign and 34 malignant) was performed to evaluate the ability to distinguish benign from malignant soft-tissue masses with magnetic resonance (MR) imaging. The correct histologic diagnosis was reached in 3i% of cases by one reader and in i6% of cases by the second reader. Mean sensitivity was 50% for benign masses and 80% for malignant masses. The majority of both benign and malignant masses had inhomogeneous signal intensity and at least partially irregular borders. Malignant masses uncommonly had smooth borders and homogeneous signal intensity. MR imaging can be used to evaluate the extent of softtissue masses, but most masses will require biopsy to determine if they are benign or malignant.