Intraoperative electron beam treatment for pediatric malignancies: The Ohio State University experience

PURPOSE: To report the result of intraoperative electron beam radiation therapy (IOERT) in patients with extensive pediatric tumors. METHOD: From October 1989 through June 2000, 13 children were treated with chemotherapy, maximal surgery, and 10-15 Gy IOERT at a total of 18 sites. IOERT was used for palliative purposes in 5 children with metastatic disease and in 3 others who were previously treated with external beam radiation (EBRT). The remaining five patients received definitive IOERT. Postoperative EBRT of 35.4-45 Gy was given in 5 patients. RESULTS: After a median follow-up of 42 months (range = 18-63 months), 4 patients were alive and without evidence of disease. Overall and 3 year actuarial survival rates were 31% (4/13) and 26%, respectively. Local control was achieved at 13/18 sites (72%). Poor prognostic factors included metastatic disease, recurrent disease, and the absence of adjuvant EBRT. Two children with Wilms tumors had 100% local control, disease-free survival, and overall survival without the addition of EBRT. CONCLUSION: A boost dose of IOERT allows for reduction in the dose of EBRT, thereby limiting growth-related morbidity without compromising local control or disease-free survival. Except for Wilms tumors, which achieved 100% local control and disease-free survival, adjuvant EBRT is necessary for successful local control and survival in children with soft tissue sarcomas. Based on this study and others, intraoperative irradiation should be considered for inclusion in prospective, multi-institutional trials designed to treat localized malignancies in young children.