Spine Cryoablation: Pain Palliation and Local Tumor Control for Vertebral Metastases.

Abstract

Percutaneous cryoablation has emerged as a minimally invasive technique for the management of osseous metastases. The purpose of this study was to assess the safety and effectiveness of percutaneous imaging-guided spine cryoablation for pain palliation and local tumor control for vertebral metastases. Imaging-guided spine cryoablation was performed in 14 patients (31 tumors) with vertebral metastases refractory to conventional chemoradiation therapy or analgesics, to achieve pain palliation and local tumor control in this retrospective study. Spinal nerve and soft-tissue thermal protection techniques were implemented in all ablations. Patient response was evaluated by a pain numeric rating scale administered before the procedure and 1 week, 1 month, and 3 months after the procedure. Pre- and postprocedural analgesic requirements (expressed as morphine-equivalent dosages) were also analyzed at the same time points. Pre- and postprocedural cross-sectional imaging was evaluated in all patients to assess local control (no radiographic evidence of disease at the treated sites). Complications were monitored. Analysis of the primary end points was undertaken via paired-comparison procedures by using the Wilcoxon signed rank test. Thirty-one tumors were ablated in 14 patients (9 women and 5 men; 20-73 years of age; mean age, 53 years). The most common tumor location was in the lumbar spine (n = 14, 45%), followed by the thoracic spine (n = 8, 26%), sacrum (n = 6, 19%), coccyx (n = 2, 6%), and cervical spine (n = 1, 3%). There were statistically significant decreases in the median numeric rating scale score and analgesic usage at 1-week, 1-month, and 3-month time points (P < .001 for all). Local tumor control was achieved in 96.7% (30/31) of tumors (median follow-up, 10 months). Two patients had transient postprocedural unilateral lower extremity radiculopathy and weakness. Percutaneous imaging-guided spine cryoablation is a safe and effective treatment for pain palliation and local tumor control for vertebral metastases.