Single-center phase 2 trial of five-day preoperative radiation therapy for patients with high-risk soft tissue sarcoma

Standard preoperative radiotherapy (RT) for high-risk soft tissue sarcoma (STS) is delivered over 5 weeks, which can be a logistical challenge for patients. A phase 2 trial at University of California, Los Angeles evaluated long-term toxic effects and clinical outcomes associated with a shorter 5-day, dose-equivalent preoperative RT regimen. In this nonrandomized trial of 110 patients, median follow-up for the initial and expansion cohorts was 64.2 and 30.0 months, respectively. Major wound complications occurred in 33 patients (30.0%); at 2 years, 14 of 74 evaluable patients (18.9%) developed grade 2 or higher toxic effects. Two-year local control rate was 92.4% (95% CI 86.3-96.5), and time to wound closure exceeded 6 months for 15 of 110 patients (13.6%). The authors conclude that these findings suggest 5-day preoperative RT was associated with favorable long-term clinical outcomes, but its potential impact on time-to-wound closure should be assessed in a randomized study.