Bone density and fracture risk following SBRT for non-spine bone metastases

Yilin Cao; Gregory C Stachelek; Wei Fu; Daniel Y Song; Russell K Hales; K Ranh Voong; Jeffrey J Meyer; Harry Quon; Chen Hu; Kristin J Redmond

Bone density and fracture risk following SBRT for non-spine bone metastases

J Radiosurg SBRT. 2021;7(3):199-206.

Authors

Affiliations

¹ Johns Hopkins University School of Medicine, Department of Radiation Oncology and Molecular Radiation Sciences, Baltimore, MD, USA.
² Johns Hopkins University School of Medicine, Department of Statistics and Bioinformatics, Baltimore, MD, USA.

PMID: 33898083
PMCID: PMC8055232

Abstract

Purpose/methods: This retrospective study evaluated local recurrence (LR) and fracture risk in non-spine bone metastases treated with SBRT.

Results: 181 lesions in 116 patients are reported. The median dose was 27 Gy (range 15-40) in 3 fractions (range 1-6). The cumulative incidence of LR was 2.8%, 7.2% and 12.5% at 6 mo, 1 yr and 2 yrs. Fractures occurred in 11 lesions (6%). Radioresistant histology and increasing PTV predicted for LR on univariate analysis, while rib location was associated with control. Increasing PTV remained a significant predictor for LR on multivariate analysis. Univariate predictors of fracture risk included female gender, lytic lesions and poorer KPS. Average CT-approximated L1 trabecular attenuation in patients with fracture was significantly lower than in patients without fracture (112.2 vs. 142.6 Hounsfield units).

Conclusion: In the largest series to date, we report excellent local control for SBRT to non-spine bone metastases and a novel relationship between CT-based bone quality assessment and fracture risk.

Keywords: SBRT; fracture; non-spine bone.