NBTXR3 Crystalline Nanoparticles and Radiation Therapy in Treating Randomized Patients in Two Arms With Soft Tissue Sarcoma of the Extremity and Trunk Wall

RATIONALE: Radiation therapy given before surgery of soft tissue sarcoma decreases the size of the tumor mass and the presence of malignant cells in its peripheral region. NBTXR3 and radiation therapy may kill more cancer cells and increase the tumor shrinkage rendering surgery more feasible or easier and achieve better local control of the tumor. PURPOSE: This phase II/III is a prospective randomized, multi-center, open-label and active controlled two arms study in patients with locally advanced soft tissue sarcoma (STS) of the extremity and trunk wall. Patients will be randomized to receive either NBTXR3 as intratumor injection, activated by external beam radiation therapy or external beam radiation therapy alone, as preoperative treatment. Once the radiotherapy treatment is completed, tumor surgery will be performed in all patients.