Observation Versus Post-surgery Radiotherapy After Complete Exeresis in Soft Tissues Members Sarcoma

Inclusion Criteria: * Soft tissue sarcoma members histologically confirmed * Tumor primitive complete excision with margins greater than or equal to 10 mm in the soft tissue in all directions during the initial surgery. A sub-centimeter margin is authorized under an anatomic barrier (fascia, fascia, inter-osseous membrane, periosteum), if surgery is R0 a margin sub-centimeter depth is allowed for superficial tumors if the underlying fascia RESECTED is not invaded. * Primitive tumors without breaking initial tumor and without tumor residue in the systematic recovery in case of incomplete initial excision margins or doubtful * WHO less than or equal to 2 * Age greater than or equal to 18 years * Review extension negative (normal chest CT) * Information and monitoring possible * Patient affiliated to social security Exclusion Criteria: * Previously treated local sarcoma relapse * Visceral or lymph node metastases * pre-operative treatment (chemotherapy or radiotherapy) * PNET, alveolar rhabdomyosarcoma, Darrier-Ferrand sarcoma * excision margins of less than 10 mm in one direction or doubtful or unspecified, except under an anatomic barrier (fascia, fascia, inter-osseous membrane, periosteum), if surgery is R0 and tumors if the superficial fascia underlying RESECTED is not invaded. * Break-tumor during the initial surgery, or residual tumor at second surgery * Chemotherapy * Delay between surgery R0 margins greater than or equal to 1 cm (initial surgery or recovery) and the start of radiotherapy exceeding 8 weeks * History of radiation on the Member * History of cancer (except carcinoma in situ of the cervix and basal cell skin cancer or in complete remission for over 5 years) * Pregnant Women * Patients under guardianship or curatorship