Preoperative Spatially Fractionated Radiation Therapy (SFRT) in Soft Tissue Sarcoma (neoSFRT-SARC)

The goal of this prospective, single-arm, phase II trial is to evaluate whether a preoperative regimen combining spatially fractionated radiation therapy (SFRT) with subsequent surgery can improve outcomes in patients with large (≥5 cm) limb/trunk soft tissue sarcoma (STS). Currently, there is a lack of standardized SFRT-based protocols for operable or borderline-resectable large STS, and optimal dose-fractionation schedules, timing to surgery, differential efficacy by resectability status, and the induced systemic immune response remain undefined. Patients will receive 5 fractions of SFRT to the primary tumor, followed by definitive surgery. The main questions are: * Can this SFRT-first approach increase the 1-year disease-free survival (DFS) compared with historical controls? * What are the pathologic complete response (pCR) rate, overall survival (OS), and treatment-related safety profile? * What immune mechanisms are engaged by SFRT, as reflected by dynamic changes in peripheral immune cell subsets and cytokines? Participants will undergo SFRT, then surgery, with serial blood sampling for immune monitoring.

NCT Number	NCT07501026
Lead Sponsor	Second Affiliated Hospital, School of Medicine, Zhejiang University
Conditions	Sarcoma
Enrollment	22 participants
Start Date	2026-03-16
Primary Completion	2028-03-16 (estimated)
Study Completion	2029-03-16 (estimated)
Updated on ClinicalTrials.gov	2026-03-30