Percutaneous tumor curettage and interstitial delivery of samarium-153 coupled with kyphoplasty for treatment of vertebral metastases.
OBJECT
The object of this study was to investigate the use of a minimally invasive technique for treating metastatic tumors of the vertebral body, aimed at relieving pain, preventing further tumor growth, and minimizing the adverse effects of systemic use of samarium-153 ((153)Sm).


METHODS
The procedure is performed in the same fashion as a kyphoplasty, using a unilateral extrapedicular approach under local anesthesia/mild general sedation, with the patient in the lateral decubitus position. The tumor is accessed as in a standard kyphoplasty. The side is chosen according to the location of the metastasis. Prior to inflation of the balloon the tumor is debulked by percutaneous curettage. Balloon inflation is carried out as per standard kyphoplasty in an attempt to create a larger space and reduce a possible kyphotic deformity. Three mCi of (153)Sm-EDTMP (ethylenediaminetetramethylenephosphonic acid) is then mixed with bone cement (polymethylmethacrylate) and injected into the void created by the balloon tamp.


RESULTS
Twenty-four procedures were performed in 19 patients. There was reliable and reproducible delivery of the radiolabeled (153)Sm-EDTMP to the metastatic site, without spillage. The procedure was safe. There were no procedure-related complications. There was no hematological toxicity with the low doses of (153)Sm used. Pain improved in all patients. The long-term results related to tumor control continue to be investigated.


CONCLUSIONS
Combined percutaneous debulking of confined vertebral metastases and administration of local (153)Sm is feasible and safe. Furthermore, this technique leads to immediate relief of cancer-related pain and may help prevent or slow down the progression of vertebral metastatic tumors.