Safety and Efficacy of Preoperative SBRT and Radical Surgery for Soft Tissue Sarcoma of Extremities

This study is testing whether giving targeted radiation (called SBRT) before surgery leads to better outcomes for people with aggressive soft tissue sarcomas (cancer of the muscles or connective tissue) in their arms or legs. **You may be eligible if...** - You are 18 or older - You have been diagnosed with a high-grade (aggressive) soft tissue sarcoma in your arm or leg - You have NOT yet had surgery, chemotherapy, or any other cancer treatment - You are in good overall health (able to care for yourself and do light activity) - You are willing to provide tumor tissue and blood samples **You may NOT be eligible if...** - Your sarcoma is small, low-grade, or near the skin surface and can be removed with simple surgery - The cancer has spread to other parts of your body - You have already had surgery or cancer treatment - You have HIV, are pregnant or breastfeeding, or have an active infection - You cannot lie flat (required for radiation treatment) - You have a serious immune system condition Talk to your doctor to see if this trial is right for you.