Radiosurgical decompression of metastatic epidural compression

Abstract

Surgical decompression of metastatic epidural compression (MEC) improved ambulatory function. Spine radiosurgery can accurately target the epidural tumor and deliver high radiation doses for tumor control. Therefore, a clinical trial was performed to quantitatively determine the degree of epidural decompression by radiosurgery of metastatic epidural compression. Sixty-two patients with a total of 85 lesions of metastatic epidural compression were treated. Epidural compression was diagnosed by magnetic resonance imaging (MRI) scans. Main criteria of inclusion were neurological status with muscle power 4 of 5 or better. Radiosurgery was performed to the involved spine segment, including the epidural mass with median dose of 16 Gy (range 12-20 Gy) in a single session. All patients had prospective clinical follow-up, ranging from 1-48 months (median 11.5 months), and 36 patients had pretreatment and post-treatment imaging, ranging from 2-33 months (median 9.3 months). Primary endpoints were epidural tumor control and thecal sac decompression. The mean epidural tumor volume reduction was 65 +/- 14% at 2 months after radiosurgery. The epidural tumor area at the level of the most severe spinal cord compression was 0.82 +/- 0.08 cm(2) before radiosurgery and 0.41 +/- 0.06 cm(2) after radiosurgery (P < .001). Thecal sac patency improved from 55 +/- 4% to 76 +/- 3% (P < .001). Overall, neurological function improved in 81%. This study demonstrated a radiosurgical decompression of epidural tumor. Although neurosurgical decompression and radiotherapy is the standard treatment in patients with good performance, radiosurgical decompression can be a viable noninvasive treatment option for malignant epidural compression.