ESTRO 2025 - Abstract Book

S1672

Clinical - Sarcoma & skin cancer & malignant melanoma

ESTRO 2025

Keywords: neoadjuvant radiotherapy, predictive role, sarcoma 1534

Digital Poster Long-term outcomes of neoadjuvant hypofractionated radiotherapy combined with chemotherapy in extremity soft tissue sarcomas. Maria Leticia Gobo Silva 1,2 , Celso Abdon Lopes de Mello 1,3 , Fernando A. Batista Campos 1,3 , Samuel Aguiar Jr 1,4 , Suely Akiko Nakagawa 1,5 , Antonio Geraldo Nascimento 1,6 , Felipe D´Almeida Costa 1,6 , Bruna Elisa Catin Kupper 1 , Ademar Lopes 1,4 1 Reference Center for Sarcomas and Bone Tumors, ACCamargo Cancer Center, Sao Paulo, Brazil. 2 Department of Radiation Oncology, ACCamargo Cancer Center, Sao Paulo, Brazil. 3 Department of Clinical Oncology, ACCamargo Cancer Center, Sao Paulo, Brazil. 4 Division of Surgery, Department of Sarcoma, ACCamargo Cancer Center, Sao Paulo, Brazil. 5 Division of Surgery, Department of Orthopedics, ACCamargo Cancer Center, Sao Paulo, Brazil. 6 Department of Anatomic Pathology, ACCamargo Cancer Center, Sao Paulo, Brazil

Purpose/Objective: To report long-term outcomes of an institutional protocol 1 using hypofractionated radiotherapy (hypo-RT) combined with chemotherapy (ChT) for treating extremity soft-tissue sarcomas (ESTS).

Material/Methods: From 2015 to 2024, 23 patients with histologically confirmed, non-metastatic ESTS were treated following our institutional protocol. After multidisciplinary tumor board discussions and informed consent, patients received three neoadjuvant cycles of doxorubicin and ifosfamide, with hypo-RT (25 Gy in 5 fractions) administered on day 1 of the second cycle. The primary endpoint was disease-free survival, while secondary outcomes included pathologic response, rates of wound complications (WC), and morbidity. Results: The baseline clinical characteristics, surgical outcomes, and pathological findings of the patients are summarized in Figure 1.