Focused Ultrasound to Promote Immune Responses for Undifferentiated Pleomorphic Sarcoma

Inclusion Criteria: 1. Men and women \>= 18 years old. 2. Eastern Cooperative Oncology Group (ECOG) performance-status score of 0-1. 3. Subjects must have either 1) a biopsy-proven new diagnosis of undifferentiated pleomorphic sarcoma (UPS) (within the last 6 months) or 2) a lesion highly suspicious for metastatic UPS based on CT or MRI imaging (within the last 6 months). 4. Target tumor \>= 2 cm in maximum diameter and \<= 20 cm in maximum diameter. 5. Target tumor accessible to the ExAblate device in the soft tissues of the chest, abdomen, pelvis, or upper or lower extremities. 6. Target tumor must be \> 1 cm from any critical structure. Critical structures are defined as skin, major nerve/vascular bundles, nerve roots, any solid organ, and any portion of the bowel. 7. Target tumor must be clearly visible by non-contrast magnetic resonance imaging (MRI) 8. For patients with newly diagnosed, not previously treated UPS, tumor must be deemed to be surgically resectable by tumor board documentation or surgeon's note. 9. To clarify, patient's being treated with institutional standard neoadjuvant chemotherapy may be included in this study if all other inclusion/exclusion criteria are met. * Note: There has never been a prospective study comparing patients receiving chemotherapy to those not receiving chemotherapy in the neoadjuvant setting for soft tissue sarcoma. Our local institutional standard is to treat patients with neoadjuvant chemotherapy prior to surgical resection when tumors are \> 5 cm in maximal dimension and within deep muscular compartments. Our institutional standard is to treat patients with doxorubicin plus ifosfamide for younger patients (typically \<50 years old) and gemcitabine plus taxotere for older patients (typically \>= 50 years old). Exclusion Criteria: 1. Subjects requiring systemic treatment with corticosteroids or other immunosuppressive medications within 14 days of Magnetic Resonance-guided Focused Ultrasound (MRgFUS) treatment date. 2. History of interstitial lung disease or other active malignancy (may confound immune response results). 3. History of previous malignancies (except non-melanoma skin cancers) (may confound immune response results). 4. All toxicities attributed to prior anti-cancer therapy other than alopecia and fatigue must have resolved to grade 1 (NCI CTCAE version 4) or baseline. 5. Subjects must have recovered from the effects of major surgery or significant trauma at least 14 days before the study procedure. 6. Subjects with an acute medical condition expected to hinder them from completing the study, unstable cardiovascular status, and severe cerebrovascular disease. 7. Treatment with any investigational agent within 28 days of the treatment procedure. 8. Any absolute contraindications for study magnetic resonance imaging (MRI) per standard University of California, San Francisco (UCSF) departmental MRI safety guidance (https://radiology.ucsf.edu/patient-care/patient-safety/mri) and additionally: * Metal in other parts of body that will cause safety issues * Claustrophobia * Weight \> 400 pounds (lb) or 181.4 kilograms (kg). * Pregnancy * Known intolerance or allergy to magnetic resonance (MR) contrast agent (gadolinium chelates) 9. Unable to safely receive anesthesia/sedation for the treatment, or known intolerance or allergy to medications used for sedation/anesthesia. 10. Unable to verbally communicate with the investigator and staff. 11. For Group 1 Patients (newly diagnosed disease) only: Have received neoadjuvant radiotherapy or planning to receive neoadjuvant radiotherapy.