Optimizing local control in Ewing sarcoma: a critical discussion of radiotherapy and surgical approaches with proposed decision-making algorithm; a narrative review

Ewing sarcoma (ES) is a rare, aggressive bone malignancy where local control remains central to cure. Modern systemic therapy has improved 5-year overall survival for localized disease to ~ 70%, but outcomes vary by tumor site, size, and patient age. Surgery offers durable control when negative margins (R0) can be achieved without major functional loss, while radiotherapy (RT) is essential for unresectable tumors, close/positive margins, or anatomically challenging locations. This narrative review critically appraises the efficacy, limitations, and late effects of RT and surgery, synthesizing data from cooperative group analyses, retrospective series, and contemporary guidelines. Advances in RT, including IMRT/VMAT, proton beam therapy, and precise target delineation, have enhanced tumor coverage and reduced toxicity, though late effects (growth disturbance, fractures, endocrine sequelae, and secondary malignancies) remain concerns, particularly in children. Surgical outcomes depend heavily on margin status and anatomical site, with adjuvant RT improving control in R1/R2 or pelvic cases. Based on this synthesis, a pragmatic, risk-adapted decision algorithm is proposed: surgery is preferred for achievable R0 resection with acceptable function; RT is indicated when resection is morbid or margins compromised; adjuvant RT is reserved for positive/close margins or high-risk sites; and whole-lung irradiation remains selective for lung-dominant remission. Multidisciplinary decision-making, adherence to standardized RT protocols, and long-term survivorship monitoring are emphasized. Future research should prioritize prospective, multi-institutional trials with uniform outcome definitions and extended follow-up, aiming to refine modality selection, minimize late effects, and improve quality of life. This framework provides a transparent, margin-anchored, anatomy-informed pathway for optimizing local control while preserving long-term outcomes in ES patients.