Efficacy and safety of radiotherapy dose escalation among pediatric and young adult patients with Ewing sarcoma

Local control for patients with Ewing sarcoma (EWS) who present with large tumors (≥ 8 cm) is suboptimal with standard radiation therapy (RT) doses of 54-55.8 Gy. A study at St. Jude Children’s Research Hospital (Memphis, TN) evaluated RT dose escalation for newly diagnosed EWS patients aged 30 years or younger with large tumors. The median RT dose was 64.8 Gy (range 59.4-69.4). All patients received systemic chemotherapy. The 5-year cumulative incidence of local failure was 6.6%, with 5-year EFS and OS rates 42% and 64.2%, respectively. Only one patient had a grade 4 toxicity, a secondary malignancy. The authors conclude that among pediatric and young adult EWS patients with large tumors, dose-escalated RT provides high rates of local control, while maintaining a tolerable toxicity profile.