Stereotactic body radiotherapy for painful spinal metastases showed high pain response rates in a single-arm phase II study.

This single-centre, single-arm phase II study enrolled 34 patients with painful spinal metastases from solid tumours, defined by a pain score of 2 or higher on a 0-10 scale. The intervention involved re-irradiation using stereotactic body radiotherapy (SBRT). The primary outcome was the pain response rate assessed at 6 months, with secondary outcomes including complete response, local failure rate, and grade 3 toxicities. Follow-up occurred at 6.0 months.

In the evaluable patient population, the pain response rate was 84% at 3 months and 83% at 6 months. In the intention-to-treat analysis, the pain response rate was 60% at 3 months and 43% at 6 months. Complete response rates were 48% at 3 months and 56% at 6 months in evaluable patients, or 34% and 29% respectively in the intention-to-treat analysis. The local failure rate at 6 months was 7%.

Regarding safety, two patients (6%) experienced grade 3 toxicities. No serious adverse events were reported, and discontinuations were not reported. The overall tolerability was described as acceptable. The study did not report p-values, confidence intervals, or absolute numbers for the primary and secondary outcomes beyond the specific toxicity count.

Key limitations include the single-centre setting, single-arm design, and small sample size of 34 patients. No comparator group was included, and funding or conflicts of interest were not reported. The study authors note that these results warrant larger randomized trials against conventional radiotherapy to establish practice relevance. Due to the observational nature of the single-arm design, causal language is avoided, and the certainty of the evidence is limited by the Phase II trial status.