ESTRO 2025 - Abstract Book

S1674

Clinical - Sarcoma & skin cancer & malignant melanoma

ESTRO 2025

The median age was 54 years (range: 21–75), with 80% having a Karnofsky Performance Status (KPS) of 90–100. Median follow-up time was 62 months (range: 6.7–93). At the last follow-up, 17 patients (74%) were alive without local or systemic disease, while three died from metastatic disease and two (8.5%) experienced local recurrence (Figure 2).

Common chemotherapy-related adverse events included grade 1–2 nausea, vomiting, fatigue, mucositis, and alopecia. Febrile neutropenia occurred in 17.5% of patients, leading to the suspension of the final chemotherapy cycle for one patient. Acute skin toxicity from radiotherapy was absent in 56.5% of patients. Grade 1 erythema occurred in 17.4%, and grade 2 or grade 3 skin reactions were observed in 13% each, with no grade 4 toxicity reported. All patients completed radiotherapy, followed by surgery at a median of 7 weeks post-chemotherapy. According to EORTC-STBSG scoring 2 , eight patients (35%) had no residual viable tumor, including subtypes such as myxoid liposarcoma (3), pleomorphic liposarcoma (2), pleomorphic sarcoma (1), synovial sarcoma (1), and Late toxicity included grade 1 subcutaneous fibrosis in 43.5% and grade 2 fibrosis in 17.5%. One patient underwent surgery for a femur fracture and necrosis within the radiation field, resulting in grade 4 joint stiffness. Nonetheless, 70% reported no joint stiffness or edema. Conclusion: Despite elevated WC rates, this treatment approach is feasible, well-tolerated, and yields high rates of limb preservation (91.5%), local control (91.5%), and pathologic complete response of 35%. Limitations include the small sample size and absence of correlation between pathologic findings and outcomes. myxofibrosarcoma (1). Eight patients had 10–49% viable cells, and seven had ≥50%. Major WC 3 occurred in nine patients (39%), all involving lower extremity lesions.