Intergroup Ewing's Sarcoma Study: local control related to radiation dose, volume, and site of primary lesion in Ewing's sarcoma.

One hundred ninety-three patients with localized Ewing's sarcoma treated at participating instutitions of the Intergroup Ewing's Sarcoma Study form the basis for this report. All patients received radiation therapy to the primary lesion and were randomized to receive vincristine, actinomycin-D, and cyclophosphamide (VAC) plus adriamycin (Regimen I); VAC alone (Regimen II); or VAC and bilateral pulmonary irradiation (Regimen III). Local control was achieved in 96% of the patients in Regimen I, and 86% of the patients in both Regimens II and III. The median duration of follow up was 83 weeks and median survival time was 172 weeks. Incremental doses of irradiation did not result in significant changes in the rate of local control of primary lesions. The local control rate was the same (92%) for tumors treated by means of whole-bone irradiation or with at least 5 cm of free margin around the lesion. The local control rate decreased to 79% for lesions treated with less than 5-cm margin. Excellent control was obtained for lesions involving the skull or spine (100%), and distal bones (fibula, 96% and tibia, 91%). Less favorable control rates were noted for pelvic and humeral lesions (84% and 79%, respectively). Bilateral pulmonary irradiation for subclinical disease played a role in lowering the incidence of lung metastases from 38% to 20% for patients treated with VAC. Lung metastases were similarly decreased (10%) when adriamycin was added to VAC chemotherapy.