Early response assessment after CyberKnife stereotactic radiosurgery for symptomatic vertebral hemangioma by quantitative parameters from dynamic contrast-enhanced MRI

Purpose: The present study aimed to explore the value of DCE-MRI to evaluate the early efficacy of CyberKnife stereotactic radiosurgery in patients with symptomatic vertebral hemangioma (SVH).

Methods: A retrospective analysis of patients with spinal SVH who underwent CyberKnife stereotactic radiosurgery from January 2017 to August 2019 was performed. All patients underwent DCE-MRI before treatment and three months after treatment. The parameters included volume transfer constant (K^trans), transfer rate constant (K_ep), and extravascular extracellular space volume fraction (V_e).

Results: A total of 11 patients (11 lesions) were included. After treatment, six patients (54.5%) had a partial response, five patients (45.4%) had stable disease, and three patients (27.3%) presented with reossification. K^trans and K_ep decreased significantly in the third month after treatment (p = 0.003 and p = 0.026, respectively). ΔK^trans was -46.23% (range, -87.37 to -23.78%), and ΔK_ep was -36.18% (range, -85.62 to 94.40%). The change in V_e was not statistically significant (p = 0.213), and ΔV_e was -28.01% (range, -58.24 to 54.76%).

Conclusion: DCE-MRI parameters K^trans and K_ep change significantly after CyberKnife stereotactic radiosurgery for SVH. Thus, DCE-MRI may be of value in determining the early efficacy of CyberKnife stereotactic radiosurgery.