Stereotactic Radiotherapy for Locally Recurrent and Metastatic Soft Tissue Sarcoma

Background Approximately half of soft tissue sarcoma (STS) patients experience local relapse or develop distant metastases during the course of the disease. The radioresistance of the majority of STS tumors necessitates increased biologically effective doses (BEDs) to achieve favorable outcomes. These doses can be safely delivered using stereotactic radiotherapy (SRT) techniques. Methods The outcome of 36 locally and distantly recurrent STS lesions in 16 patients treated with SRT was reviewed. A variety of STS histologies and locations were included, involving the lungs, abdomen, extremities, trunk, spine, and brain. A median marginal BED of 96 Gy₁₀ (range: 48-151 Gy₁₀) was delivered, calculated using an α/β ratio of 10 Gy. Kaplan-Meier analysis was performed to assess the local recurrence-free survival on a per-target basis. Results The median follow-up was 13 months (range: three to 27 months). Actuarial local control rates of 26/26 (100%) and 15/17 (88%) were observed at 12 and 18 months post-SRT, respectively. SRT was associated with minimal toxicities, except for one patient who presented with late skin toxicity of the upper extremity. Conclusions Results of this study indicate that SRT should be considered an effective treatment option for the management of selected locally recurrent and metastatic STS patients.