Chest Wall Reconstruction in Ewing Sarcoma Using a Radioprotective Spacer

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INTRODUCTION: Ewing sarcoma is a rare malignant tumor that primarily affects children and adolescents, and approximately 20% occur in the chest wall, where achieving local control is challenging due to the need for extensive resection and the proximity to vital organs. Adjuvant radiotherapy improves outcomes but carries a risk of severe complications such as radiation pneumonitis. Radioprotective spacers have been used for abdominal and pelvic tumors, but their use in chest wall tumors is rarely reported. We report a chest wall Ewing sarcoma case in which a radioprotective spacer using expanded polytetrafluoroethylene and a water-inflatable expander was placed to reduce radiation-related organ damage.

CASE PRESENTATION: A 15-year-old female presented with a large Ewing sarcoma arising from the left chest wall, measuring 121 × 166 × 93 mm. After diagnosis by wedge biopsy and confirmation of EWSR1::FLI1 fusion, she received neoadjuvant chemotherapy based on the JESS04 protocol. Following significant tumor shrinkage, surgical resection was performed via a 20‑cm thoracotomy. En bloc removal included the tumor, the 5th and 6th ribs, and a portion of the adjacent lung. To reconstruct the chest wall and protect adjacent organs from high‑dose postoperative radiotherapy, a novel radioprotective spacer was inserted. The spacer was constructed by sandwiching a water‑inflatable tissue expander between two expanded polytetrafluoroethylene sheets. This design provided dual functionality: it reinforced the large chest wall defect and physically distanced the left lung from the radiation field. The expander was filled with 70 mL of water to create an adjustable spacer volume and could be deflated if postoperative symptoms occurred. The patient underwent intensity‑modulated radiation therapy with a total dose of 50.4 Gy without respiratory complications. After radiotherapy, the expander was removed, while the expanded polytetrafluoroethylene sheets remained in place to maintain chest wall integrity. At 4 years postoperatively, the patient remains disease‑free and symptom‑free.

CONCLUSIONS: This case illustrates the feasibility and safety of combining a radioprotective spacer with structural chest wall reconstruction in pediatric sarcoma. The dual‑purpose design may offer an effective strategy for minimizing radiation‑related toxicity in thoracic tumors requiring multimodal treatment.