470 Changes in CT Hounsfield Unit and T Score Before and After Osteoporosis Treatment With Teriparatide or Denosumab

Abstract

INTRODUCTION: In 2004, 10 million individuals over the age of 50 were estimated to suffer from osteoporosis in the US and this prevalence was expected to rise dramatically. Currently the standard for diagnosis is by defining the bone mineral density using a dual energy xray absorptiometry (DEXA) machine. Literature has demonstrated that the hounsfield (HU) on a CT of the lumbar spine vertebrae can be an extremely sensitive and specific metric towards identifying those with osteoporosis or osteopenia, however further evaluation of this measure and how it changes with osteoporosis treatment, specifically with newer treatment options (ie denosumab and teriparatide) is needed. METHODS: Chart review was completed for patients started on denosumab or teriparatide between 2014 and 2022. Patients were included if they were started on denosumab or teriparatide for osteoporosis or osteopenia treatment and had a DEXA and CT available at some point pre or post treatment. Demographic, medication information, pre and post treatment both DEXA based T scores and CT Hounsfield units (HU) at T12-L3 were collected. ANOVA and T tests were used for statistical analysis. RESULTS: A total of 38 patients were included in our study. Average premedication HU at T12, L1, L2, L3 were 106, 94, 92, and 83 respectively. Those treated with teriparatide showed a significant (p = 0.03) decrease in HU at L1 over the study period compared to those treated with Denosumab. CONCLUSIONS: HUs can serve as a widely available surrogate to both diagnose and monitor the treatment of osteoporosis.