Hemithorax irradiation for Ewing tumors of the chest wall.

PURPOSE: In the Cooperative Ewing's Sarcoma Study 86 and the European Intergroup Cooperative Ewing's Sarcoma Study 92, hemithorax irradiation (RT) was performed in patients with Ewing tumors of the chest wall involving the pleura or contaminating the pleural cavity. In a retrospective analysis, the outcomes of these patients were evaluated and compared with those of patients with chest wall tumors who did not receive hemithorax RT. METHODS AND MATERIALS: Between 1985 and 1996, 138 patients presented with nonmetastatic Ewing tumors of the chest wall. They were treated in a multimodal treatment regimen that included polychemotherapy and local therapy depending on the tumor characteristics. Hemithorax RT was performed at a dose of 15 Gy for patients <14 years old and 20 Gy for patients >or=14 years old. Forty-two patients received hemithorax RT (Group 1) and 86 patients did not (Group 2). The data were insufficient for the other 10 patients.
RESULTS: Comparing both groups, the initial pleural effusion, pleural infiltration, and intraoperative contamination of the pleural space were significantly more frequent in Group 1. The event-free survival rate after 7 years was 63% for patients in Group 1 and 46% for patients in Group 2 (not statistically significant). The 7-year local relapse rate (including combined local-systemic relapses) was 12% in Group 1 and 10% in Group 2; the corresponding systemic relapse rates were 22% and 39%.
CONCLUSION: Patients with chest wall tumors who received hemithorax RT were negatively selected; yet the rate of event-free survival was better for patients who received hemithorax RT than for those who did not (although the difference was not statistically significant). This result was due to a reduction of metastases, mainly lung metastases. Local control was equivalent between the two groups. These favorable results have caused us to continue using hemithorax RT to treat high-risk patients with Ewing tumors of the chest wall.