Vertebral compression fracture after stereotactic ablative radiotherapy in patients with oligometastatic bone lesions from hepatocellular carcinoma

•Stereotactic ablative radiotherapy (SABR) for oligometastatic vertebral bone lesions from hepatocellular carcinoma (HCC) resulted in a substantial rate of new vertebral compression fracture (VCF) development and pre-existing VCF progression.•VCF developed in 14 (12%) of 118 VCF-naïve patients and progressed in 20 of the 26 with pre-existing VCF, and the median time of VCF development was 6 months.•Pre-existing VCF was significant risk factor for VCF development after SABR for bone metastasis, which require special attention in patient care. Stereotactic ablative radiotherapy (SABR) is popularly used to treat bone metastasis. Despite its efficacy, adverse events, including vertebral compression fracture (VCF), are frequently observed. Here, we investigated VCF risk after SABR for oligometastatic vertebral bone metastasis from hepatocellular carcinoma. A total of 84 patients with 144 metastatic bone lesions treated at three institutions between 2009 and 2019 were retrospectively reviewed. The primary endpoint was VCF development, either new or progression of a pre-existing VCF. VCFs were assessed using the spinal instability neoplastic score (SINS). Among 144 spinal segments, 26 (18%) had pre-existing VCF and 90 (63%) had soft tissue extension. The median biologically effective dose (BED) was 76.8 Gy. VCF developed in 14 (12%) of 118 VCF-naïve patients and progressed in 20 of the 26 with pre-existing VCF. The median time to VCF development was 6 months (range, 1–12 months). The cumulative incidence of VCF at 12 months with SINS class I, II and III was 0%, 26% and 83%, respectively (p