Stereotactic high-dose irradiation for intramedullary metastases.

Unlabelled: Intramedullary metastases (IMM) lead to severe neurological symptoms. They are extremely rare in clinical practice. Optimal management of such patients is not clearly defined. Surgery, chemo- and radiotherapy are the main options.

Objective: To study the results of stereotactic high-dose irradiation for IMM considering local control of metastases, neurological status and life expectancy.

Material And Methods: Nineteen patients with 29 IMMs underwent high-dose irradiation (Cyber Knife G4 and TrueBeam STx devices) between 2016 and 2022. There were 1-10 fractions, radiation dose 14.0-35.0 Gy with isodose 70-100%. Local control and new spinal cord metastases were assessed using contrast-enhanced MRI. Clinical status and neurological functions were assessed using the Karnofsky and McCormick scales.

Results: Local control rates were 91% and 78% after 6 and 12 months, respectively. Overall survival after treatment was 7.3 months, 6- and 12-month overall survival - 58% and 37%, respectively. In addition, 8 patients were available for follow-up. Of these, 6 ones demonstrated improvement or stabilization of neurological function after treatment. The main cause of death was progression of the underlying disease. No significant treatment-related toxic effects were observed.

Conclusion: High-dose irradiation is a safe, effective and time-saving treatment for IMM. Considering unadvisable surgical methods and chemotherapy for this pathology, we can recommend high-dose irradiation for patients with spinal cord metastases.