Pre-operative Hypofractionated Proton Therapy

This study is being done to examine whether proton therapy for certain kinds of sarcomas (extremity and trunk soft tissue) is safe and effective. As part of the study, patients will have five fractions of proton therapy before the participants have surgery for the sarcoma. The study will measure wound complications and functional outcomes / quality of life after the procedures. Patients will be asked to complete questionnaires about the treatment and quality of life from the time of enrollment until about two years after surgery. Otherwise, the participants will have standard of care follow ups with the treatment team.

Inclusion Criteria: * Adult patients (≥18 years of age) * Patients with primary or locally recurrent extremity or truncal soft tissue sarcoma * WHO/ECOG status ≤2 Exclusion Criteria: * History of prior local radiation therapy * Inability to tolerate treatment position for duration of simulation or treatment * Tumor originating in retroperitoneal location * Patients planned for systemic therapy including chemotherapy, targeted agents, and immunotherapy * Co-existing malignancy or treated malignancy in the last 2 years expected to limit life expectancy; does not include completely resected cutaneous basal cell carcinoma, squamous cell carcinoma, in situ breast or cervical malignancies, or other pathologies at the discretion of the investigators. * Confirmed pregnancy.