Prognostic Value of Metabolic Response Measured by FDG-PET-CT in Patients with Breast Cancer Liver Metastasis Treated with Stereotactic Body Radiotherapy

Abstract

OBJECTIVETo investigate the impact of metabolic response measured by 18-fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET-CT) in patients with breast cancer liver metastasis (BCLM) treated with stereotactic body radiotherapy (SBRT). METHODSThe medical records of 17 patients with BCLM treated with SBRT between March 2013 and October 2017 were investigated retrospectively. Patients received SBRT for their liver metastasis, and thereafter, a second FDG-PET-CT was performed for response assessment in a median of 4.1 (2.2-8.2) months. A total of 54 Gy in three fractions were delivered to liver metastatic lesions. The standardized uptake value (SUV) and survival rates were evaluated. RESULTSAfter a median follow-up time of 11.5 (3.2-48.9) months, there was a significant difference between preand post-SBRT SUVs (p<0.001). Complete metabolic response was observed in 14 (82%) patients, partial metabolic response was observed in 2 (12%) patients, and stable metabolic disease/progressive metabolic disease was observed in 1 (6%) patient at post-treatment PET-CT. The 1-and 2-year overall survival rates were 68% and 57%, respectively, and the 1-and 2-year progression-free survival rates were 38% and 25%, respectively. CONCLUSIONPET-CT is an effective tool for response monitoring in patients with BCLM treated with SBRT.