Study of Magnetic Resonance Image and Computed Tomography-Guided Stereotactic Body Radiation Therapy for Abdominopelvic Sarcomas (MARS Trial)

This study (called the MARS Trial) tests a specialized type of targeted radiation treatment called Stereotactic Body Radiation Therapy (SBRT), guided by MRI and CT scans, to precisely treat sarcomas (rare soft tissue or bone cancers) in the abdomen or pelvis before surgery. **You may be eligible if...** - You have been diagnosed with sarcoma (confirmed by biopsy) that involves the abdomen or pelvis - Your cancer is either a new case or has come back (recurrent) - Your tumor can be surgically removed - You are 12 years or older - You are in reasonably good health (able to perform basic daily activities) - If you are a woman who could become pregnant, you must have a negative pregnancy test **You may NOT be eligible if...** - You are actively being treated for a separate cancer - The area to be treated has already received radiation in the past Talk to your doctor to see if this trial is right for you.