This paper is a progress report on the role of
radiation therapy (RT) in local
tumor control and the decreased incidence of pulmonary
metastasis in 251 patients entered in the Intergroup
Ewing's Sarcoma Study. All were followed for more that 1 year, and their RT records were reviewed. Doses to the primary
tumor in the range of 4,500--6,500 rad were administered over approximately 5 to 6 weeks in combination with 4 drugs, i.e.,
vincristine (VCR),
dactinomycin (DAC),
cyclophosphamide (CY), and
adriamycin, or only the first 3. One group of patients received the 3 drugs and bilateral pulmonary irradiation (approximately 1,500 rad in 2 wk). Preliminary analysis showed a local primary
tumor control of approximately 90%. Patients with lesions in the pelvis and humerus had local failure rates of 13% (7 of 54) and 21.4% (6 of 28), respectively. The treatment groups differed significantly in the incidence of pulmonary
metastasis. Patients treated with the 4 drugs (regimen 1) had a 14% incidence, whereas 42% of those treated with only 3 drugs (regimen 2) developed pulmonary
metastases. Of all patients treated with 3 drugs and pulmonary irradiation (regimen 3), 18% showed lung
metastases. The study indicated that intensive
chemotherapy and RT significantly improved the local control and survival of patients with localized
Ewing's sarcoma. However, the high incidence of
metastasis indicated the need for more effective systemic
chemotherapy for further improvement of treatment results. More studies are needed so we can define the volume to be treated and the optimal dose of irradiation to determine a therapeutic strategy that will yield optimal survival and
tumor control with the fewest sequelae.