Radiation therapy for Ewing's sarcoma: results from Memorial Sloan-Kettering in the modern era

To evaluate the outcomes of patients with Ewing's sarcoma family of tumors (ESFT) treated with modern radiotherapy techniques with MRI along with optimal chemotherapy.

The records of all 60 patients with ESFT who received radiation to the primary site between 1990 and 2004 were reviewed. All patients received chemotherapy, including vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide. Radiation was used as the sole modality for local control in 31 patients and was given either before (n=3) or after surgical resection (n=26) in the remainder. All patients had MRI and CT scan-based treatment planning, and 43% received intensity-modulated radiation therapy. Radiation doses ranged from 30 Gy to 60 Gy (median, 51 Gy), and 35% received hyperfractionated radiotherapy.

Median age was 16 years (range, 2-40 years). Because of selection bias for radiotherapy, the majority of primary tumors were centrally located (72%): spine (n=18), pelvis (n=15), extremities (n=12), chest wall (n=5), head and neck (n=5), and other (n=5). Thirty-eight percent of patients presented with metastatic disease, and 52% of primary tumors were >or=8 cm. Actuarial 3-year local control was 77%. The presence of metastases at diagnosis was an adverse prognostic factor for local control (84% vs. 61%, p=0.036). No other predictive factors for local failure were identified. In patients without metastatic disease, 3-year disease-free and overall survival rates were 70% and 86%, respectively, whereas in patients with metastases they were both 21%. Follow-up of surviving patients was 6-178 months (median, 41 months).

In this unfavorable cohort of ESFT patients, radiation therapy was an effective modality for local control, especially for patients without metastases. The presence of metastases at diagnosis is a predictive factor not only for death but also for local failure.