An Imaging Agent (Fluorodopa F 18) With Positron Emission Tomography/Magnetic Resonance Imaging for Assessing Treatment Response in Patients With High-Grade Soft Tissue Sarcomas

Inclusion Criteria: * PRE-ELIGIBILITY - INCLUSION CRITERIA: * Age \>= 18 years * Histological confirmation of newly diagnosed soft tissue sarcoma or recurrent soft tissue sarcoma \>= 1-year post-treatment * Tumors \> 1 cm in diameter in largest dimension located midline within the torso or neck, retroperitoneal, or lower extremities * Operable sarcoma, planning to receive surgery with or without neoadjuvant RT/chemotherapy at Mayo Clinic Florida. Systemic therapy is allowed during radiotherapy * Provide informed written consent * Willingness to participate in mandatory imaging studies at Mayo Clinic Florida Exclusion Criteria: * POST-ELIGIBILITY - EXCLUSION CRITERIA: * 18F-DOPA PET uptake deemed as unacceptable for quantitative assessment * Unable to undergo an 18F-DOPA PET/MRI scan due to standard MRI restrictions, such as for those with certain implanted devices, those who cannot fit inside the bore, or those with severe claustrophobia * Any of the following: * Pregnant women * Nursing women * Men or women of childbearing potential who are unwilling to employ adequate contraception