What is the Optimal Management of Metastatic Spine Patients With Intermediate Spinal Instability Neoplastic Scores: To Operate or Not to Operate?

Study Design: Systematic review. Objective: In patients with extradural metastatic spine disease, we sought to systematically review the outcomes and complications of patients with intermediate Spinal Instability Neoplastic Score (SINS) lesions undergoing radiation therapy, percutaneous interventions, minimally invasive surgeries, or open spinal surgeries. Methods: Following PRISMA guidelines for systematic reviews, MEDLINE, EMBASE, Web of Science, the Cochrane Database of Systematic Reviews and the Cochrane Center Register of Controlled Trials were queried for studies that reported on SINS intermediate patients who underwent: 1) radiotherapy, 2) percutaneous intervention, 3) minimally invasive, or 4) open surgery. Dates of publication were between 2013-22. Patients with low- or high-grade SINS were excluded. Outcome measures were pain score, functional status, neurological outcome, ambulation, survival, and perioperative complications. Results: Thirty-nine studies (n = 4554) were included that analyzed outcomes in the SINS intermediate cohort. Radiotherapy appeared to provide temporary improvement in pain score; however, recurrent pain led to surgery in 15%–20% of patients. Percutaneous vertebral augmentation provided improvement in pain. Minimally invasive surgery and open surgery offered improvement in pain, quality of life, neurological, and ambulatory outcomes. Open surgery may be associated with more complications. There was limited evidence for radiofrequency ablation. Conclusion: In the SINS intermediate group, radiotherapy was associated with temporary improvement of pain but may require subsequent surgery. Both minimally invasive surgery and open spinal surgery achieved improvements in pain, quality of life, and neurological outcomes for patients with spine metastases. Open surgery may be associated with more complications.