Soft tissue sarcomas are relative rare tumors with an incidence of almost 1% of all malignancies. Although their etiology is not well understood, studies regarding the effect of ionizing radiation, showed their capacity to induce sarcomas in soft tissues, after several years from the treatment of other primary tumor. Their early diagnosis could be achieved by genetic analysis of radio-induced chromosomal translocations specific to each histological type. Dose-response curves reveals the dynamics of the process, taking into consideration the beam energy and linear energy transfer.