Stereotactic radiosurgery (SRS) for primary spinal bone tumors: a systematic review and meta-analysis

While surgery is a vital component in the treatment of most primary spinal bone tumors (PSBTs), it is only one aspect of a comprehensive management plan. Optimizing patient outcomes often requires a multidisciplinary approach, incorporating medical oncology and interventional radiology. The use of stereotactic radiosurgery (SRS) is typically considered when patients are either poor surgical candidates or have recurrent or unresectable tumors. However, the use of SRS and its efficacy remains relatively unclear. Our aim with this study is to investigate the therapeutic response among PSBTs treated with SRS. We performed a systematic literature search in the databases Medline, Embase (Ovid), Scopus, Web of Science Advance and Cochrane Central from inception to July 8, 2024. We included studies that reported on outcomes of SRS in patients with PSBTs and meta-analyzed the proportions of recurrence, progression, and local control (LC). The quality of included studies was assessed using the MINORS tool for non-randomized studies. We identified 5 studies with relevant data for our meta-analysis, and our results consist of overall analyses that compile all the relevant data, and a subgroup analysis for chordomas. The compiled pooled proportion of LC was 0.81 [95% CI: 0.55; 0.94], and in the chordoma subgroup, it was 0.82 [95% CI: 0.59; 0.93]. The compiled pooled proportion of recurrence was 0.14 [95% CI: 0.03; 0.47], and in the chordoma subgroup, it was 0.14 [95% CI: 0.03: 0.47]. The compiled pooled proportion of progression was 0.26 [0.15; 0.42], and in the chordoma subgroup, it was 0.22 [95% CI: 0.10; 0.41]. Our meta-analysis suggests that treating PSBTs with SRS is associated with promising results in terms of LC (81%), but 14% of the cases had recurrence, and 26% showed tumor progression. Thus, SRS as a primary treatment modality for PSBTs still requires further modifications to further enhance results and improve patient outcomes.