Consensus recommendations regarding local and metastasis-directed therapies in the management of relapsed/recurrent Ewing sarcoma.

Limited randomized or prospective data are available to guide local/metastasis directed therapy (LMDT) in relapsed/recurrent Ewing sarcoma (RR-ES), resulting in uncertainty regarding best clinical practice for these patients. This report reviews the available literature on LMDT approaches and provides consensus recommendations regarding therapeutic decision making, timing, and indications for the use of LMDT in the management of RR-ES. LMDT should be considered on a case-by-case basis to assess appropriateness, optimal timing/modality, palliative versus curative intent, and its role in relation to chemotherapy. One commonly used LMDT is radiotherapy (RT), which can be delivered through standard, hypofractionated, or stereotactic techniques based on factors including prior RT, tumor size, and/or location. Chemotherapy can be combined with RT, although prospective data are limited in the relapse setting. Surgery for LMDT not only addresses the tumor but also provides tissue for analysis, though the potential surgical morbidity based on location, extent of resection, and recovery complications should be considered. Interventional radiology approaches also can procure tumor tissue while delivering LMDT; there are several different procedures available based on the location, size, and extent of disease. Finally, a combination of LMDT approaches can be used for patients with RR-ES. Decisions regarding the management of RR-ES should involve a multidisciplinary team and factor in the burden of disease, progression-free interval, life expectancy, toxicity profiles of LMDT, and quality of life. In such patients, informed and shared decision making with patients and their families is paramount.