Study of Neoadjuvant Proton and Carbon Ion Radiation for Treating Retroperitoneal Soft Tissue Sarcoma Randomized Phase II Trial Evaluating Safety and Effectiveness Before Surgery

What this Trial Is About

Researchers are evaluating the safety and feasibility of a hypofractionated, accelerated radiation treatment using protons or carbon ions for patients with retroperitoneal soft tissue sarcomas. This study is a randomized, open, prospective phase II trial focused on the incidence of serious Grade 3-5 toxicities and therapy termination rates during neoadjuvant radiation followed by tumor surgery. The special physical properties of protons and carbon ions may help protect nearby organs such as the intestines, kidneys, and liver during treatment. Participants are randomly assigned to one of two groups one receiving proton radiation and the other receiving carbon ion radiation. Both groups receive a total dose of 39 Gy delivered in 13 fractions with a standard dose of 3.0 Gy per fraction, six times per week. The treatments use active beam guidance targeting the tumor before surgical removal. During the study, participants will be monitored for adverse events, treatment completion, and secondary outcomes including tumor control, progression-free survival, disease-free survival, overall survival, and quality of life using the EORTC QLQ-C30 questionnaire. The primary outcome is the incidence of serious toxicities within 12 months after radiation treatment, with ongoing assessments of safety and treatment feasibility throughout the study period.

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