PRIMARY OBJECTIVE:~I. Determine the correlation between 18F-DOPA PET/MRI quantitative metrics after neoadjuvant treatment (pre-surgery) with percent tumor necrosis.~SECONDARY OBJECTIVE:~I. Compare the changes in 18F-DOPA PET/MRI quantitative metrics between baseline (before radiotherapy [RT]) and after RT, but before surgery with percent tumor necrosis.~OUTLINE:~Patients receive 18F-DOPA intravenously (IV) and undergo PET/MRI over 60 minutes before standard of care radiotherapy and/or before standard of care surgery.
This study evaluates the use of a new imaging agent called fluorodopa F 18 (18F-DOPA) with positron emission tomography/magnetic resonance imaging (PET/MRI) for assessing treatment response in patients undergoing standard of care radiation therapy and/or surgery for high-grade soft tissue sarcomas that are new or that have come back (recurrent). Though there have been improvements in treatment options for soft tissue sarcomas, there is currently a need for a non-invasive way to determine a patient's potential benefit from receiving one of these treatments. 18F-DOPA with PET/MRI allows a patient's tumor to be visualized and their response to a given treatment assessed.