Digital tomosynthesis for follow-up imaging of upper thoracic spine metastases: A novel case application

We report a case demonstrating the utility of digital tomosynthesis (DTS) for follow-up imaging of a metastatic tumor in the upper thoracic spine. A 64-year-old woman presented with progressive lower extremity numbness and gait disturbance. Imaging revealed a pathologic fracture of the T3 vertebra secondary to metastatic lung cancer. The patient was treated with a cervicothoracic brace, radiation therapy, denosumab, and osimertinib. DTS performed 2 weeks after admission revealed a lytic lesion, and follow-up DTS at 16 weeks demonstrated bone sclerosis, indicating a positive treatment response. The patient remained neurologically intact and was able to discontinue brace use. Conventional radiography is limited in visualizing the upper thoracic spine due to shoulder overlap, while CT involves higher radiation exposure. DTS enabled early detection of lytic changes and subsequent sclerosis, demonstrating its value in visualizing treatment response during follow-up. This case highlights the potential of DTS as a practical follow-up imaging modality in oncologic spine care.