Minimal Access Spine Surgery (MASS) for Decompression and Stabilization Performed as an Out-Patient Procedure for Metastatic Spinal Tumours Followed by Spine Stereotactic Body Radiotherapy (SBRT): First Report of Technique and Preliminary Outcomes

We report a novel approach in the treatment of spinal metastases with epidural disease and mechanical instability using a combined minimal access spine surgery (MASS) technique followed by spine stereotactic body radiotherapy (SBRT). This study was performed as a retrospective review of the first ten consecutive patients treated with this combined approach. The MASS technique was based on a tubular retraction system to gain access for decompression and mechanical stabilization achieved using methyl-methacrylate (MMA) applied under direct visualization. SBRT consisted of one to five image-guided high dose per fraction treatments. Eight patients were symptomatic at baseline. Pain, disability, and quality of life (QOL) were prospectively determined using the visual analogue score (VAS), Oswestry Disability Index (001), and Short-Form-36 version 2, respectively. The median follow-up was 13 months (range, 3-18). MASS successfully decompressed each patient. The median blood loss was 335 ml. Following MASS, the median time to SBRT treatment planning was 6.5 days and subsequent median time to treatment was 7 days. Local control was observed in 7 of the 10 patients. Improvements in VAS, ODI and QOL were observed post-SBRT. We report preliminary efficacy for our MASS-SBRT combined approach for patients with spinal metastases, mechanical pain and epidural disease.