Postoperative Stereotactic Radiosurgery for Spinal Metastases: Clinical Outcomes, Failures, and Analysis of Local Control

Abstract

Abstract INTRODUCTION Stereotactic radiosurgery (SRS) is a viable treatment modality for patients with spinal metastases. SRS is increasingly being used in multimodal management. Results of postoperative SRS following separation surgery has been reported but clinical outcomes and local control for a more heterogenous surgical sample (ie, anterior approaches, anterior column reconstruction, revision surgery after previous SRS) are lacking in the literature. We present data on clinical outcomes and local tumor control at a major cancer center following contemporary surgical approaches for spine metastases. METHODS After IRB approval, retrospective review of patients between 2012 and 2017 was performed at a single institution. Demographics, tumor histology, survival/recurrence rates, clinical outcomes, and complications were analyzed. RESULTS Eighty-six consecutive patients treated with SRS after spine surgery were identified. Mean age was 64. Radiation dose was 18 Gy in 1 fraction using 6 MV photons with a 24 Gy boost. Follow-up was 3 to 84 mo, with average time between surgery (11.1% anterior, 88.9% posterior approach) and SRS 3 wk. Evaluation was every 3 mo after treatment with CT or MRI. 1- and 2-yr survival rates were 57% and 38%, respectively. Overall rate of local recurrence was 12.7%. Multivariate analysis revealed tumor location (thoracic) and histology (lung carcinoma, colon, or melanoma) as significant prognostic factors for local control and survival. The surgical/medical complication rates were 14.3% and 19.0%. The most common complication after SRS was acute pain flare. Rate of hardware failure was 6.3%. A total of 3 patients developed procedure-related neurological deficits, but there were no cases of radiation myelopathy. There were no differences in local control with anterior column reconstruction. CONCLUSION SRS is effective following all types of surgery for metastases, not just separation surgery. SRS should be considered in the postoperative management for spinal metastases given low complications and high local control rate (∼87%) irrespective of histology.