Definitive Radiotherapy in the Management of Non-Resectable or Residual Retroperitoneal Sarcomas: Institutional Cohort Analysis and Systematic Review.

RT provided satisfactory local disease control with acceptable treatment tolerance in patients with primary or recurrent non-resectable/residual RPS and represents a valuable treatment modality in the selected group of patients. Additional RT modalities i.e. BT, particle therapy, MRI-guided RT, or GRID/Lattice RT may be introduced to improve local control and further minimize toxicity.