Efficacy and safety of percutaneous microwave ablation and cementoplasty in the treatment of painful spinal metastases and myeloma

BACKGROUND AND PURPOSE: Painful spinal metastases are a common cause of cancer-related morbidity. Percutaneous ablation presents an attractive minimally invasive alternative to conventional therapies. We performed a retrospective review of 69 patients with 102 painful spinal metastases undergoing microwave ablation and cementoplasty to determine the efficacy and safety of this treatment. MATERIALS AND METHODS: Procedures were performed between January 2015 and October 2016 with the patient under general anesthesia using image guidance for 102 spinal metastases in 69 patients in the following areas: cervical (n 2), thoracic (n 50), lumbar (n 34), and sacral (n 16) spine. Tumor pathologies included the following: multiple myeloma (n 10), breast (n 27), lung (n 12), thyroid (n 6), prostate (n 5), colon (n 4), renal cell (n 3), oral squamous cell (n 1), and adenocarcinoma of unknown origin (n 1). Procedural efficacy was determined using the visual analog scale measured preprocedurally and at 2- 4 weeks and 20 -24 weeks postprocedure. Tumor locoregional control was assessed on follow-up cross-sectional imaging. Procedural complications were recorded to establish the safety profile. RESULTS: The median ablation time was 4 minutes 30 seconds 7 seconds, and energy dose, 4.1 1.6 kJ. Median visual analog scale scores were the following: 7.0 1.8 preprocedurally, 2 1.6 at 2- 4 weeks, and 2 2.1 at 20 -24 weeks. Eight patients died within 6 months following the procedure. Follow-up imaging in the surviving patients at 20 -24 weeks demonstrated no locoregional progression in 59/61 patients. Two complications were documented (S1 nerve thermal injury and skin burn). CONCLUSIONS: Microwave ablation is an effective and safe treatment technique for painful spinal metastases. Further studies may be helpful in determining the role of microwave ablation in locoregional control of metastases.