Background: Stereotactic body radiotherapy (SBRT) is emerging as a novel treatment option in metastatic soft tissue sarcoma (STS). The aim of our study was to evaluate the effectiveness of exclusive SBRT on disease control and survival in oligometastatic (≤ 3 synchronous lesions) STS. Materials and methods: In total, 16 consecutive patients, accounting for 26 metastases (including 21 lung and 5 lymph node or soft tissue metastases), were treated at our institution with SBRT. Patient- and treatment-related characteristics were collected. Local control (LC), overall survival (OS), distant metastases-free survival (DMFS), and time to initiation of chemotherapy or best supportive care (corrected disease-free survival, cDFS) were assessed. Results: Four-year OS was 54% and median OS was 69 months [95% confidence interval (CI) 20–118 months]. LC of 26 lesions at 4 years was 78%. Median DMFS and cDFS were 17 (95% CI 5–30 months) and 28 months (95% CI 5–52 months), respectively. Disease-free interval < 24 months from primary tumor treatment to first metastasis was the only predictor of reduced LC, cDFS, and OS (p = 0.022, 0.023, and 0.028, respectively). No acute or chronic grade ≥ 3 toxicity was observed. Median follow-up was 36 months (IQR 18–71 months). Conclusions: In patients with oligometastatic STS, SBRT yields satisfying local control with minimal toxicity. Median OS was 69 months. Repeated SBRT may be considered to extend disease-free and systemic therapy-free interval. Increased time from primary tumor to first metastasis identifies patients with potentially greater benefit from SBRT.

Additional Metadata
Keywords Oligometastases, Radiotherapy, Soft tissue sarcoma, Stereotactic body radiotherapy
Persistent URL dx.doi.org/10.1007/s11547-018-0912-5, hdl.handle.net/1765/114232
Journal La Radiologia Medica
Citation
Loi, M, Duijm, M, Baker, S. (Sarah), Rossi, L, Grunhagen, D.J, Verhoef, C, & Nuyttens, J.J.M.E. (2018). Stereotactic body radiotherapy for oligometastatic soft tissue sarcoma. La Radiologia Medica, 123(11), 871–878. doi:10.1007/s11547-018-0912-5