Neoadjuvant Irradiation of Retroperitoneal Soft Tissue Sarcoma With Ions Retro-Ion

With retroperitoneal sarcomas, the patient benefits from neoadjuvant radiotherapy. Due to the special physical properties of particles (protons and C12 carbon ions), in particular the steep lateral dose drop, an improved protection of adjacent risk organs is e.g. Intestine, kidneys, liver etc. during the process of applying radiotherapy is possible. The primary study objective is to demonstrate the safety and conduct of study treatment and the incidence of Grade 3-5 NCI-CTC-AE toxicity and / or termination of preferred therapy for any reason. Further target parameter is the proportion of applied therapies without the occurance of degree 3-5 NCI-CTC-AE(s). The patients are randomized 1: 1 into the two arms (carbon ions vs. protons). Patients receive 39 Gy in (SD 3.0 Gy) in 6 fractions per week. Secondary study objectives are local control (LC), local progression-free survival from the start of therapy (LPFS), disease-free survival (DFS), overall survival (OS) and quality of life (QoL) determined according to the EORTC-Quality of Life Questionaire (QLQ)- C30 questionnaire.