Stereotactic ablative radiotherapy for pulmonary metastasis from sarcoma: a retrospective comparison with metastasectomy.

Abstract

Recent studies report excellent local control (LC) and favorable toxicities of stereotactic ablative radiotherapy (SABR) for pulmonary metastasis (PM) from sarcoma. This study compared the LC and survival of SABR and metastasectomy for sarcoma PM. We analyzed the LC rates of 54 PMs treated with SABR between 2008 and 2022. For survival analysis, we compared 14 patients who received SABR as first-line treatment with 61 patients who underwent metastatectomy. For SABR-treated PMs, a median total dose of 55Gy (range, 48-60) was administered over 3-10 fractions. Median follow-up for LC in SABR-treated PMs was 19.2months (range, 0.8-124.0), and the 2-year LC rate was 92.2%. No patients experienced toxicities of grade 3 or higher. The median age of the patients in the survival analysis was 73years (range, 42-83) in the SABR group and 54years (range, 19-78) in the metastasectomy group (p < 0.001). PMs in the "gray zone" were more common in the SABR group (35.7%) than in the metastasectomy group (8.2%) (p = 0.029). The median follow-up for survival analysis was 44.8months (interquartile range, 21.5-66.4). The 3-year rates of LC and overall survival were 92.3% and 57.3% in the SABR group and 89.2% and 75.9% in the metastasectomy group (p = 0.807, 0.224), respectively. The out-of-field intrapulmonary failure-free survival and extrapulmonary systemic failure-free survival rates at 3years were not significantly different (p = 0.673, 0.386). SABR for sarcoma PM demonstrated excellent LC with acceptable toxicity. Survival rates of SABR were comparable to those of metastasectomy.