Single fraction radiosurgery of epidural spinal cord compression: Tumor control and neurologic outcome

Abstract

2041 Purpose: Spine radiosurgery improves the pain and quality of life in spine metastasis. Phase II study was performed to determine the clinical efficacy of radiosurgery for malignant epidural spinal cord compression. Method: Total 67 patients with 93 lesions of epidural spinal cord compression at the solitary spine level were accrued. All patients had pathology-proven malignancy and had epidural tumor seen on MRI or CT scan. For radiosurgery, grossly visible tumor including the involved spine was treated with single fraction radiosurgery dose of 14–20 Gy. Spinal cord dose constraint was 10 Gy to 10% partial volume of the cord. Followup included neurological exam and imaging studies every 2 months. Endpoints were radiographic tumor control and neurological outcome. Median followup time was 8 months (2–30 months). Results: Objective radiographic tumor response was seen in 82% of patients. At 2 months, complete response was in seen 27%, partial response in 30%, and minimal response in 23%, Epidural tumor progressed in 6% at or the adjacent spine level. Thecal sac patency (= decompression effect) seen on T2-weighted MR image was improved in 82% of the lesions. There was average 68% volumetric reduction of tumor at the level of most severe cord compression. This tumor reduction opened the thecal sac patency to average 75% following radiosurgery, compared to 45% before radisourgery (p<0.05). Majority of patients with neurological deficit prior to radiosurgery were ambulatory with an improved neurological function or remained clinically stable. There was one case of likely long-term radiation-induced myelopathy 13 months after radiosurgery. Conclusion: Single fraction radiosurgery achieves significant tumor response and decompressive effect of spinal cord compression. Even minimal tumor response relieves the spinal cord compression and potential neurologic improvement. Spine radiosurgery can be a viable treatment option for spinal cord compression. No significant financial relationships to disclose.