Inclusion Criteria:  Histologically confirmed newly diagnosed intermediate to high grade soft tissue sarcoma localized to the extremities, for which the standard treatment is a combination of RT and surgery (deep seated and/or > 5cm in largest tumor diameter and/or an anticipated close resection margin and/or grade II/III according to the FNCLCC definition); Patients staged by at least a CT scan of the chest (and a CT scan of the abdomen, if deemed indicated according to local practices, e.g. in case of a myxoid liposarcoma). Staging may also be performed by FDG-PET scanning and or total body MRI scans. This staging procedure should not reveal metastatic disease. If, however, a low metastatic burden is detected such that this does not preclude the application of both preoperative RT and definitive surgery, patients are allowed to participate; WHO Performance Status ≤ 2; Able and willing to undergo preoperative RT; Able and willing to undergo definitive surgery; Able and willing to comply with regular follow-up visits; Able and willing to swallow and retain oral medication;  Exclusion Criteria:  Patients with any type soft tissue sarcoma located above the clavicles. Prior malignancies; except another malignancy and disease-free for ≥ 5 years, or completely resected non-melanomatous skin carcinoma or successfully treated in situ carcinoma; Patients with recurrent sarcomas who underwent prior RT to the target lesion (if the primary sarcoma was managed by surgery only and no perioperative RT, patients are eligible); Ewing sarcoma and other PNET family tumors, rhabdomyosarcomas (both pediatric and adult), bone sarcomas; Any psychological, familial, sociological or geographical condition potentially hampering compliance with the study protocol and follow-up schedule; those conditions should be discussed with the patient before registration in the trial; Female patients who are pregnant or breast feeding;