Background: Metastasectomy is standard of care for pediatric patients with metastatic sarcoma with limited disease. For patients with unresectable disease, stereotactic body radiotherapy (SBRT) may serve as an alternative. Herein, the authors report the results of a prospective, multi-institutional phase 2 trial of SBRT in children and young adults with metastatic sarcoma. Methods: Patients aged >3 years and ≤40 years with unresected, osseous metastatic nonrhabdomyosarcoma sarcomas of soft tissue and bone were eligible. Patients received SBRT to a dose of 40 Gray (Gy) in 5 fractions. Local control (LC), progression-free survival (PFS), and overall survival (OS) were calculated using the Kaplan-Meier method. Results: Fourteen patients with a median age of 17 years (range, 4-25 years) were treated to 37 distinct metastatic lesions. With a median follow-up of 6.8 months (30.5 months in surviving patients), the Kaplan-Meier patient-specific and lesion-specific LC rates at 6 months were 89% and 95%, respectively. The median PFS was 6 months and the median OS was 24 months. In a post hoc analysis, PFS (median, 9.3 months vs 3.7 months; log-rank P =.03) and OS (median not reached vs 12.7 months; log-rank P =.02) were improved when all known sites of metastatic disease were consolidated with SBRT compared with partial consolidation. SBRT was well tolerated, with 2 patients experiencing grade 3 toxicities. Conclusions: SBRT achieved high rates of LC in pediatric patients with inoperable metastatic nonrhabdomyosarcoma sarcomas of soft tissue and bone. These results suggest that the ability to achieve total consolidation of metastatic disease with SBRT is associated with improved PFS and OS.
Bibliographical noteFunding Information:
Matthew M. Ladra has received honoraria for speaking engagements from ProKnow for work performed outside of the current study. Sara R. Alcorn is employed by the Johns Hopkins University School of Medicine; has received grants from Elekta, the National Institutes of Health (grant 5KL2TR001077), and the Radiation Oncology Institute (ROI2020‐913); has received nonfinancial support from AngioDynamics; and has received personal fees from the Allegheny Health Network for work performed outside of the current study. Iris C. Gibbs has received honoraria and paid speaking fees from Accuray Inc for work performed outside of the current study. Stephanie A. Terezakis has received institutional research funding from ASELL LLC for work performed outside of the current study. The other authors made no disclosures.
© 2020 American Cancer Society
- neoplasm metastasis