• Age 18-75 years.

• ECOG Performance Status score of 0-1.

• Histologically or cytologically confirmed diagnosis of high-grade soft tissue sarcoma (G2-G3), classified as moderately sensitive or higher to chemotherapy (or determined suitable for radiotherapy and chemotherapy by the investigator). Typically includes histological types such as synovial sarcoma, vascular sarcoma, adult fibrosarcoma, intramuscular chondrosarcoma, leiomyosarcoma, liposarcoma, undifferentiated pleomorphic sarcoma, hepatic undifferentiated embryonic sarcoma, and unclassified soft tissue sarcomas.

• Clinical confirmation of soft tissue sarcoma suitable for surgical resection after multidisciplinary assessment.

• Presence of at least one measurable lesion according to RECIST v1.1 assessment criteria and suitable for ≥40 Gy/f radiotherapy (or determined suitable for radiotherapy by the investigator).

• Laboratory and other examinations:Hematology: Absolute neutrophil count ≥1500/μL, platelet count ≥100,000/μL. Pulmonary function: No respiratory difficulty at rest, no reduced exercise tolerance, resting pulse oximetry \>94% in room air.

• Renal function (creatinine clearance or radioisotope GFR ≥70 mL/min/1.73 m² or serum creatinine within normal limits according to age/gender). Liver function (total bilirubin ≤1.5 × ULN, AST or ALT \<2.5 × ULN). Cardiac function: Left ventricular ejection fraction (LVEF) ≥50%.

• Signed informed consent and good compliance.

• Reproductive-age women must use reliable contraception or have a negative pregnancy test (serum or urine) within 7 days before enrollment and agree to use appropriate contraception during the study and for 8 weeks after the last dose of investigational drug.