Use of Imaging in the Management of Metastatic Spine Disease With Percutaneous Ablation and Vertebral Augmentation

Abstract

Radiologists should be familiar with pertinent imaging findings related to the percutaneous management of metastatic spine disease.

Benign Spine Lesions: Advances in Techniques for Minimally Invasive Percutaneous Treatment

“…The necrotic ablated volume shows no enhancement on postcontrast imaging, with variable signal intensity on T1-and T2-weighted sequences, depending on the relative amounts of sclerotic bone, residual vascular and yellow marrow, and hemorrhagic products. 63 The ablated volume is surrounded by a T1-hypointense, T2-hyperintense rim that enhances after contrast administration and corresponds histologically to granulation tissue or vascular fibrosis. 63 Cement appears as a signal void in the ablation cavity on all pulse sequences.…”

“…63 The ablated volume is surrounded by a T1-hypointense, T2-hyperintense rim that enhances after contrast administration and corresponds histologically to granulation tissue or vascular fibrosis. 63 Cement appears as a signal void in the ablation cavity on all pulse sequences. Residual or recurrent tumor typically appears as T2-hyperintense, enhancing tissue at the margin of the ablation cavity; however, granulation tissue and vascular fibrosis can have identical MR imaging signal and enhancement characteristics, 63 and the decision to proceed with further treatment should be based on clinical evaluation.…”

Radiographic Local Control of Spinal Metastases with Percutaneous Radiofrequency Ablation and Vertebral Augmentation

“…In each case, the goal was to perform overlapping ablations that encompassed the entire volume of tumor on cross-sectional imaging and an additional 3-mm margin to account for microscopic tumor spread. 9 A bipedicular approach was used when tumor extended across the sagittal vertebral body midline and could not be entirely ablated with an adequate margin from a unipedicular approach (Fig 1). Ablations were performed with the STAR Tumor Ablation System (DFINE, San Jose, California).…”

“…Additionally, T1-hypointense, T2-hyperintense signal and/or enhancement at the margin of the ablation cavity on follow-up MR imaging were categorized as local con-trol failure unless these findings remained stable on subsequent imaging, retraction of epidural tumor was seen, or a PET/CT scan was available demonstrating absence of associated FDG uptake (Fig 1). 9 To serve as an internal control, posttreatment cross-sectional imaging was also reviewed for evidence of systemic disease progression, including enlargement of visceral or intracranial metastases or osseous metastases that were not ablated.…”

“…8 Cement is then instilled through the same percutaneous cannula to stabilize or prevent associated pathologic fracture. 9,10 The tandem procedure can be performed in an outpatient setting with the patient under conscious sedation, requires minimal recovery, and does not hinder or delay adjuvant therapies such as radiation or systemic chemotherapy. Multiple case series have shown decreased pain scores after RFA and vertebral augmentation of spinal metastases, [11][12][13][14][15] but evidence that percutaneous therapy achieves local tumor control is limited to case reports and small case series without internal controls.…”