Introduction Almost one third of all cancer patients will develop a spinal metastasis at some time in their lives. Traditionally, management of these metastatic lesions has been multi-modal, involving a combination of oral pain medication with radiation as well as the potential for surgical intervention if there is mechanical instability or compression of neural elements. Recently, the application of percutaneous radiofrequency ablation (RFA) with vertebroplasty has been described as a safe method for treatment for acute reduction in pain associated with these lesions. This potential for acute pain control prior to radiation presents an attractive option to bridge the palliation gap when treating patients with painful spinal metastases. The majority of previous studies examining RFA have described the use of a monopolar probe to deliver the thermal energy. Studies describing the safe and effective use of bipolar RFA are lacking, and this lack of knowledge can be intimidating to providers as they adopt this new technology. Herein we describe our single-institution experience with bipolar RFA for the treatment of spinal metastases and highlight technical considerations we have found important during the first phase of our adoption of this new technology.

Methods The interventional radiology database from June 2017 to December 2017 was reviewed for patients who were treated with bipolar RFA for painful spinal metastases. After Institutional Review Board approval, these records were reviewed for: age, primary cancer type, location of spinal metastases, size of ablated lesions, presence and extent of epidural extension, procedural characteristics of bipolar RFA and subsequent application of poly-methylmethacrylate (PMMA) if indicated as well as follow up imaging when available.

Results Over review of the medical records identified 10 patients with 14 ablated vertebral metastases who were treated at our institution. The average age of these patients was 63.3 years old and there were a wide variety of primary cancers, 5 patients had breast or prostate and the remaining 5 patients each had a different primary. All patients presented with back pain and 5 of the patients presented with concomitant leg pain. The average visual analog score (VAS) was 7.0 pre-intervention which improved to 3.0 post-intervention in the patients for which VAS was recorded. There was 1 occurrence of symptomatic cement extravasation causing radiculopathy, which eventually resolved on follow-up.

Conclusion RFA for the treatment of spinal metastases is a safe therapy for palliation of back pain. There are several nuances to the application of RFA and subsequent vertebroplasty to spinal metastatic disease compared to a traditional osteoporotic compression fracture. Careful attention to detail when adopting this new technology is important in preventing potentially avoidable complications from cement embolization or extravasation.

Disclosures J. West: None. G. Greeneway: None. K. Fargen: None. S. Quintero-Wolfe: None.