Indications for and delivery of adjuvant therapies for pediatric nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) have been derived largely from adult studies; therefore, significant concern remains regarding radiation exposure to normal tissue. We reported long-term treatment outcomes and toxicities for pediatric and young adult patients with high-grade NRSTS who were treated with limited-margin radiotherapy in a prospective trial. In this study, 62 patients (ages 3-22 years) with predominantly high-grade NRSTS requiring radiation were treated in a phase II institutional study of conformal external-beam radiotherapy and/or brachytherapy using a 1.5-cm to 2-cm anatomically constrained margin. The estimated cumulative incidence of local failure, Kaplan-Meier estimates of survival, predictors of disease outcome determined by the competing-risk regression model, and toxicity were reported. Multivariable analysis indicated that younger age was the only independent predictor of local recurrence. The 5-year cumulative incidence of grade 3 or 4 late toxicity was 15%. The study concluded that the delivery of limited-margin radiotherapy using conformal external-beam radiotherapy or brachytherapy provides a high rate of local tumor control without an increase in marginal failures and with acceptable treatment-related morbidity.
Tinkle CL, Fernandez-Pineda I, Sykes A, Lu Z, Hua CH, Neel MD, Bahrami A, Shulkin BL, Kaste SC, Pappo A, Spunt SL, Krasin MJ. Non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) in pediatric and young adult patients: results from a prospective study using limited-margin radiotherapy. Cancer 123(22):4419-4429, 2017. PMID: 28759114.