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

Inclusion Criteria: * Age: 18 years and older * Locally Advanced Soft Tissue Sarcoma of the Extremity and Trunk Wall * All grades * Candidate to radiotherapy + surgery (ESMO guideline 2014) i.e. tumor must not have involvement of bone and / or vessel and or nerve : * Primary tumor or, * Relapsed tumor, localized out of previously irradiated area * WHO performance score 0 to 2 * Adequate function of bone marrow * Adequate renal function * Adequate hepatic function * Adequate pulmonary function * All female patients of childbearing potential must have a negative serum/urinary pregnancy test Exclusion Criteria: * Absence of written Informed Consent duly signed and dated * Patients with the following histological type: embryonal or alveolar rhabdomyosarcoma, Ewing's sarcoma, osteosarcoma or chondrosarcoma, Kaposi's sarcoma, primitive neuroectodermal tumor, angiosarcoma, aggressive fibromatosis or dermatofibrosarcoma protuberans * Soft Tissue Sarcoma of the Trunk Wall localized in the abdominal region i.e. the region defined cranially by the xiphoid process of the sternum and the costal margins, and caudally by the line joining the anterior superior iliac spines, both limited by the perpendicular lines crossing both nipples * Patient with a calculated tumor baseline volume \> 3000 mL * Metastatic disease (CT-scan / MRI verification) with life expectancy shorter than 6 months * Previous radiation therapy in relapse site of soft tissue sarcoma (no radiation re-challenge is permitted) * Concurrent treatment with any other anticancer therapy, including chemotherapy, immunotherapy, targeted therapy, gene therapy, or patients planning to receive these treatments during the study * Absence of histologically or cytologically proven cancer at the first diagnosis * Previous neoadjuvant chemotherapy treatment given as an upfront of the current treatment line * Hemolytic anemia * Autoimmune disease * Complete initial work up earlier than 4 weeks prior to patient registration * Patients unable to comply with scheduled visits, treatment plans, laboratory tests, and other study procedures * Patients participating in another clinical investigation at the time of signature of the informed consent