Stereotactic Body Radiation Therapy (SBRT) for Liver Oligometastases: outcomes and safety

Abstract Background: The aim of this study was to investigate adverse effects, progression free survival (PFS), one-year local control (LC) and one-year overall survival (OS) of patients with liver oligometastases treated with stereotactic body radiotherapy (SBRT), and whether there is a significant difference in these parameters in patients with primary colorectal cancer compared to other tumor localizations.Methods: Patients were simulated using four-dimensional computed tomography (4DCT). Using volumetric modulated arc therapy (VMAT) technique, SBRT was performed on 16 patients with <3 liver metastases. The prescribed dose was 60 Gy in 8 fractions (BED 105 Gy). Cone beam CT (CBCT) was used for image guidance before each fraction with online correction.Results: There were no adverse effects. Mean PFS for all patients, patients with primary colorectal cancer, and patients with primary non-colorectal cancer was 12.2 months (SD 8.3), 16.3 months (SD 7.9), 8.1 months (SD 6.8), respectively. There was a significant difference in the mean PFS for these two observed groups (p = 0.023). The one-year LC was 62.5%. Patients with primary colorectal cancer had the one-year LC of 87.5%, while the group of patients with primary non-colorectal cancer had the one-year LC of 37.5% (p = 0.014). The total one-year OS was 87.5%. In the group of patients with primary colorectal cancer, the one-year OS was 100%, while in the group of patients with primary non-colorectal cancer, the one-year OS was 75% (p = 0.147).Conclusion: SBRT is a safe and effective method of treating liver oligometastases.