Stereotactic Body Radiation Therapy for Sarcoma Pulmonary Metastases

Area of Science:

• Oncology
• Radiation Oncology
• Medical Physics

Background:

• Lung metastases are a common complication in sarcoma patients.
• Metastasectomy is an option for limited disease, but alternatives like SBRT are being explored.
• Limited data exists on SBRT for sarcoma lung metastases.

Purpose of the Study:

• To evaluate the outcomes of SBRT for lung metastases in sarcoma patients.
• To assess local control, overall survival, and toxicity after SBRT.
• To compare different SBRT dose/fractionation regimens.

Main Methods:

• Fifty sarcoma patients with 109 lung metastases were treated with SBRT between 2005 and 2021.
• Outcomes included local control, overall survival, and toxicity.
• Patients were divided into three dose/fractionation cohorts.

Main Results:

• High 1- and 3-year local control rates (96%/88%) and overall survival (77%/50%).
• No significant differences in outcomes or toxicity across different SBRT regimens.
• Tumor size >4 cm predicted worse local control and overall survival.
• Most failures were new metastases (64%), primarily in the contralateral lung (52%).
• 85% one-year chemotherapy-free survival; 76% avoided chemotherapy changes post-SBRT.
• Overall toxicity was low (16%).

Conclusions:

• SBRT demonstrates high local control for sarcoma lung metastases, with similar outcomes across various dose/fractionation schedules.
• SBRT is associated with prolonged chemotherapy-free survival.
• Prospective studies are needed to validate these findings.