We modelled the impact of postoperative radiotherapy (PORT) on local relapse (LR) in localised Ewing sarcoma.
We observed a significant reduction of LR in patients treated by PORT compared to surgery alone.
The benefit of PORT was particularly marked for tumours ≥ 200 ml and 100% necrosis.
A non-significant trend for benefit was observed for disease-free survival, event-free survival and overall survival.
We recommend PORT when pre-chemotherapy involved tissue volume cannot be entirely removed surgically.