Spine Instrumentation Failure After Spine Tumor Resection and Radiation: Comparing Conventional Radiotherapy with Stereotactic Radiosurgery Outcomes

OBJECTIVE: To evaluate whether stereotactic spine radiosurgery (SRS) results in lower rates of instrumentation failure or higher rates of fusion compared with surgical decompression and stabilization combined with conventional fractionated radiation (XRT) in patients with spine tumors. METHODS: The Cleveland Clinic Spine Tumor board database was retrospectively reviewed. Only patients who underwent spine surgery with instrumentation followed by either SRS or XRT and who had at least 6 months of clinical and imaging follow-up were included. RESULTS: The primary inclusion criteria were met by 15 instrumented and irradiated patients (8 SRS and 7 XRT). In the XRT group, 43% had instrumentation failure versus 0% instrumentation failure in the SRS group (P = 0.08). Excluding patients with no bone graft, fusion rates were 50% in the SRS group versus 17% in the XRT group (not significant). CONCLUSIONS: SRS precisely delivers ionizing radiation to tumors, while sparing the surrounding organs or vital structures. This study poses the question of whether a fusion site should also be considered a structure or organ at risk and whether SRS rather than XRT is more ideal in the postoperative setting. This relatively small series shows a trend toward higher fusion rates and a lower incidence of instrumentation failure with SRS and suggests that larger prospective studies are warranted.