Spatially Fractionated Radiotherapy Versus Conventional Radiotherapy in the Treatment of Soft Tissue Sarcoma

This study is a multicenter, prospective, randomized controlled phase II clinical trial designed to evaluate the efficacy and safety of Spatially Fractionated Radiation Therapy (SFRT) compared to Conventional Radiation Therapy (CRT) in the treatment of soft tissue sarcoma (STS, minimum tumor diameter ≥5 cm). A total of 106 patients were enrolled and randomized in a 1:1 ratio. The primary endpoint is the objective response rate (ORR) of the target lesion at 3, 6, 9, and 12 months post-radiotherapy, assessed using RECIST 1.1 and Choi criteria. Secondary endpoints include the 1-year local control rate (LC) of the target lesion, progression-free survival (PFS), safety (per CTCAE v5.0), and quality of life (QoL, assessed by EORTC QLQ-C30). CRT is delivered at 3.0 Gy per fraction for a total of 15-20 fractions. SFRT comprises CRT at 3.0 Gy per fraction for 15-20 fractions, augmented by weekly high-dose vertices of 8-15 Gy per fraction for 3-4 fractions, aiming to enhance tumor control and potentially stimulate immune responses. This study is a multicenter, prospective, randomized controlled phase II clinical trial designed to evaluate the efficacy and safety of Spatially Fractionated Radiation Therapy (SFRT) compared to Conventional Radiation Therapy (CRT) in the treatment of soft tissue sarcoma (STS, minimum tumor diameter ≥5 cm). A total of 106 patients were enrolled and randomized in a 1:1 ratio. The primary endpoint is the objective response rate (ORR) of the target lesion at 3, 6, 9, and 12 months post-radiotherapy, assessed using RECIST 1.1 and Choi criteria. Secondary endpoints include the 1-year local control rate (LC) of the target lesion, progression-free survival (PFS), safety (per CTCAE v5.0). CRT is delivered at 3.0 Gy per fraction for a total of 15-20 fractions. SFRT comprises CRT at 3.0 Gy per fraction for 15-20 fractions, augmented by weekly high-dose vertices of 8-15 Gy per fraction for 3-4 fractions, aiming to enhance tumor control and potentially stimulate immune responses.

NCT Number	NCT06980259
Lead Sponsor	Shandong Cancer Hospital and Institute
Conditions	Soft Tissue Sarcoma (STS)
Enrollment	106 participants
Start Date	2025-05-20
Primary Completion	2027-05-20 (estimated)
Study Completion	2028-05-20 (estimated)
Updated on ClinicalTrials.gov	2026-04-28