Stereotactic Body Radiation Therapy and Concurrent Targeted Therapy for Lung Metastases in Pediatric Sarcoma

Abstract

PurposeThe purpose of this investigation was to evaluate the efficacy and safety of stereotactic body radiotherapy (SBRT) for pulmonary metastases from pediatric sarcomas. MethodsThis study was a single institutional retrospective chart review including patients younger than 21 years of age at diagnosis who had received SBRT for pulmonary metastasis from metastatic sarcoma. Our current electronic record system was queried for all eligible patients. Primary endpoint was tumor response as defined by RECIST 1.1 criteria. Secondarily, we analyzed factors that affected tumor response as well as toxicity of treatment. Median dose was 50 Gy ranging from 45-60 Gy in 5 fractions to the planning tumor volume (PTV). ResultsThere were 7 patients, ranging from ages 6 to 21 years with a total of 14 pulmonary lesions treated with SBRT. Median and mean follow up times for the 7 patients were 10.6 months and 15.9 months respectively. The complete response rate was 50%, partial response 21%, stable disease 21%, and progressive disease 7%. Four of the seven patients were treated with concurrent systemic therapy, three of which were targeted oral therapies. Additionally, we observed that patients who were on targeted therapy such as regorafenib or pazopanib seemed to have better local control as compared to patients without. ConclusionsWith an overall response rate of 92%, SBRT provided a non-invasive effective palliative treatment option with few side effects in this small retrospective study of 7 patients. A larger prospective clinical trial is warranted to evaluate the role of SBRT in the treatment of unresectable metastatic pediatric sarcomas.