Simultaneous Bipedicular Radiofrequency Ablation Combined with Vertebral Augmentation for Local Tumor Control of Spinal Metastases

Illustration of simultaneous bipedicular RF ablation (A) depicts individual zones of resistive and conductive heating (central and peripheral ovoids, respectively) around 2 adjacent RF electrodes, resulting in a diminished convective cooling effect (ie, heat sink due to blood and CSF flow) (A, arrows). Adjacent areas of thermal spread result in reduction in the power required to conduct heat in tissue, decreased risk of thermal injury, and impedance-related issues. Axial T1-weighted fat-saturated contrast-enhanced MR imaging (B) following bilateral RF ablation using 2 straight electrodes shows ablation failure along the posterior third vertebral body centrally due to lack of confluent ablation zones (B, arrows).

An 86-year-old man with metastatic melanoma and a painful L1 lesion. Axial contrast-enhanced CT (A) shows a destructive osteolytic mass within the vertebral body with partial disruption of the posterior wall and a small component extending to the anterior central canal (A, arrow). An anteroposterior fluoroscopic image during simultaneous bipedicular RF ablation (B) shows medial articulation of electrode tips, which are 5–10 mm apart (the width of the spinous process as a landmark). Lateral fluoroscopic images (C–E) show ablation of the anterior vertebral body first (C), followed by ablation of the posterior vertebral body and pedicles (D), and vertebral augmentation (E). Axial T1-weighted fat-saturated contrast-enhanced MR images obtained 2 weeks (F) and 52 weeks (G) following treatment show local tumor control with granulation tissues along the periphery of ablation zone (F and G, arrows).