Radiation for Pulmonary Relapse in Ewing Sarcoma: A Scoping Review.

Ewing sarcoma (EWS) is the second most common primary malignant bone and soft tissue tumor. Relapsed EWS is difficult to treat, with poor long-term survival. Isolated lung relapse occurs in about a third of relapsed patients, and there is no standard of care. We aim to review the available literature with the goal of providing guidance for the management of isolated pulmonary relapsed EWS using the 2 major types of pulmonary-directed radiation: whole lung irradiation (WLI) and stereotactic body radiation therapy (SBRT). PubMed and Web of Science were reviewed for studies that evaluated patients with pulmonary relapsed or metastatic EWS who received radiation. Twelve articles met criteria for inclusion; 8 reviewed the use of WLI and 4 reviewed SBRT. Patients who received WLI had improved progression-free survival compared with those who received SBRT, though most had already achieved disease control. There were low rates of toxicity reported with both modalities. WLI appears to be beneficial in patients who have a complete resection before undergoing radiation, while SBRT is indicated to areas of active disease. We suggest future studies test a combination of SBRT in areas of active disease with low-dose WLI to decrease the risk for future metastases.