Oxycodone combined with pulsed radiofrequency for refractory cancer pain from spinal metastases: a randomized controlled study

Abstract Objectives To assess the clinical efficacy and safety of oxycodone combined with pulsed radiofrequency (PRF) in the treatment of refractory cancer pain (RCP) arising from spinal metastasis. Methods A randomized controlled trial enrolled 60 patients with RCP due to spinal metastases. Participants were randomly allocated to the oxycodone alone group (Group A, n = 30) or the oxycodone combined with PRF group (Group B, n = 30). Primary outcomes comprised pain scores on the Numerical Rating Scale (NRS) and episodes of breakthrough pain at post-treatment time points Secondary endpoints included opioid consumption, immune parameters, quality of life, and adverse event incidence. Results Group B had significantly lower NRS scores and fewer 24-h breakthrough pain episodes than Group A at post-treatment time points ( p < 0.05). The opioid consumption and 7/30-day drug escalation indices of Group B were significantly lower ( p < 0.05), with a lower dose escalation rate (46.67% vs. 73.33%, p = 0.035). Group B exhibited relatively better preserved selected T lymphocyte subset parameters (CD3⁺, CD4⁺ T cell percentages, CD4⁺/CD8⁺ ratio) and quality of life scores ( p < 0.05), with a markedly lower overall adverse reaction rate (43.33% vs. 70.00%, p = 0.037) and no serious adverse events observed. Conclusions This exploratory pilot randomized controlled trial indicated that the combination of oxycodone and PRF may contribute to improved pain control, decreased opioid consumption, and attenuated decline in lymphocyte subsets alongside enhanced quality of life in patients with spinal metastasis-related refractory cancer pain. No serious adverse events were documented. The clinical and oncological significance of the observed intergroup differences in T cell indices remains unclear. These preliminary observations require verification in larger prospective trials.