Background and aim: Calcium-suppressed imaging with dual-energy CT can visualize subtle cellular changes in the bone marrow. The purpose of this study was to investigate the application value of calcium-suppressed images in the evaluation of cancellous bone metastasis treated by stereotactic ablative radiotherapy (SABR). Patients and methods: Dual-energy CT was performed before and after SABR in 10 patients with cancellous bone metastasis from breast cancer. Signal intensities of cancellous bone metastases to skeletal muscle were compared using calcium-suppressed images. Results: The relative signal intensity of cancellous bone metastasis before SABR was 0.99 +- 0.02, while after SABR it was 0.95 +- 0.06 (P < 0.05). Visual assessment of the signal intensity of cancellous bone metastases showed a decrease in signal intensity in all cases. Conclusions: Calcium-suppressed imaging with dual-energy CT may be able to evaluate cancellous bone metastases treated by SABR.  Kulcsszavak: radiation therapy, dual energy CT, trabecular bone, tumor regression