Efficacy and Safety of Hypofractionated Preoperative Radiotherapy for Primary Locally Advanced Soft Tissue Sarcomas of Limbs or Trunk Wall

SIMPLE SUMMARY: The primary treatment of soft tissue sarcomas (STS) is radical resection. The use of adjuvant radiotherapy showed a significantly decreased incidence of local recurrence. In our previous study, we presented that preoperative hypofractionated radiotherapy is safe and efficient for treating an unselected group of patients with STS. This study aimed to assess the treatment scheme’s use in patients with primary STS treated at one institution. The preoperative radiotherapy (RT) scheme consisted of 5 Gy per fraction for a total dose of 25 Gy. Surgery was performed within 2–4 days from the last day of RT. We included 311 patients in this prospective study. In this group, with a significant percentage of patients with extensive, high-grade STS, hypofractionated preoperative radiotherapy was associated with similar local control compared to published studies dedicated to this population. The early tolerance was good, with a small number of late complications. ABSTRACT: Background: The use of adjuvant radiotherapy (RT) shows a significantly decreased incidence of local recurrence (LR) in soft tissue sarcomas (STS). This study aimed to assess the treatment scheme’s effect in patients with primary STS treated at one institution. Methods: In this phase 2 trial, 311 patients aged ≥18 years with primary, locally advanced STS of the extremity or trunk wall were assigned to multimodal therapy conducted at one institution. The preoperative RT scheme consisted of 5 Gy per fraction for a total dose of 25 Gy. Surgery was performed within 2–4 days from the last day of RT. The primary endpoint was LR-free survival (LRFS). Adverse events of the treatment were assessed. Results: We included 311 patients with primary locally advanced STS. The median tumor size was 11 cm. In total, 258 patients (83%) had high-grade tumors. In 260 patients (83.6%), clear surgical margins (R0) were obtained. Ninety-six patients (30.8%) had at least one type of treatment adverse event. LR was observed in 13.8% patients. The 5-year overall survival was 63%. Conclusion: In this group, with a significant percentage of patients with extensive, high-grade STS, hypofractionated preoperative RT was associated with good local control and tolerance.