Claudio V Sole1, Felipe A Calvo2, Alfredo Polo3, Mauricio Cambeiro4, Carmen Gonzalez5, Manuel Desco6, Rafael Martinez-Monge4. 1. Department of Radiation Oncology, Instituto de Radiomedicina, Santiago, Chile; School of Medicine, Complutense University, Madrid, Spain. Electronic address: csole@iram.cl. 2. School of Medicine, Complutense University, Madrid, Spain; Department of Oncology, Hospital General Universitario Gregorio Marañón, Madrid, Spain. 3. Service of Radiation Oncology, Hospital Universitario Ramón y Cajal, Madrid, Spain. 4. Service of Radiation Oncology, Clínica Universidad de Navarra, Pamplona, Spain. 5. School of Medicine, Complutense University, Madrid, Spain; Service of Radiation Oncology, Hospital General Universitario Gregorio Marañón, Madrid, Spain. 6. School of Medicine, Complutense University, Madrid, Spain; Department of Experimental Surgery and Medicine, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
Abstract
PURPOSE: To assess long-term outcomes and toxicity of intraoperative electron-beam radiation therapy (IOERT) in the management of pediatric patients with Ewing sarcomas (EWS) and rhabdomyosarcomas (RMS). METHODS AND MATERIALS: Seventy-one sarcoma (EWS n=37, 52%; RMS n=34, 48%) patients underwent IOERT for primary (n=46, 65%) or locally recurrent sarcomas (n=25, 35%) from May 1983 to November 2012. Local control (LC), overall survival (OS), and disease-free survival were estimated using Kaplan-Meier methods. For survival outcomes, potential associations were assessed in univariate and multivariate analyses using the Cox proportional hazards model. RESULTS: After a median follow-up of 72 months (range, 4-310 months), 10-year LC, disease-free survival, and OS was 74%, 57%, and 68%, respectively. In multivariate analysis after adjustment for other covariates, disease status (P=.04 and P=.05) and R1 margin status (P<.01 and P=.04) remained significantly associated with LC and OS. Nine patients (13%) reported severe chronic toxicity events (all grade 3). CONCLUSIONS: A multimodal IOERT-containing approach is a well-tolerated component of treatment for pediatric EWS and RMS patients, allowing reduction or substitution of external beam radiation exposure while maintaining high local control rates.
PURPOSE: To assess long-term outcomes and toxicity of intraoperative electron-beam radiation therapy (IOERT) in the management of pediatric patients with Ewing sarcomas (EWS) and rhabdomyosarcomas (RMS). METHODS AND MATERIALS: Seventy-one sarcoma (EWS n=37, 52%; RMS n=34, 48%) patients underwent IOERT for primary (n=46, 65%) or locally recurrent sarcomas (n=25, 35%) from May 1983 to November 2012. Local control (LC), overall survival (OS), and disease-free survival were estimated using Kaplan-Meier methods. For survival outcomes, potential associations were assessed in univariate and multivariate analyses using the Cox proportional hazards model. RESULTS: After a median follow-up of 72 months (range, 4-310 months), 10-year LC, disease-free survival, and OS was 74%, 57%, and 68%, respectively. In multivariate analysis after adjustment for other covariates, disease status (P=.04 and P=.05) and R1 margin status (P<.01 and P=.04) remained significantly associated with LC and OS. Nine patients (13%) reported severe chronic toxicity events (all grade 3). CONCLUSIONS: A multimodal IOERT-containing approach is a well-tolerated component of treatment for pediatric EWS and RMS patients, allowing reduction or substitution of external beam radiation exposure while maintaining high local control rates.