Preoperative Arterial Embolization of Spine Metastases Not Associated With Improved Local Control or Overall Survival in Patients Receiving Surgery Followed by Stereotactic Body Radiation Therapy.

BACKGROUND AND

OBJECTIVES

Separation surgery followed by stereotactic body radiation therapy (SBRT) for solid tumor malignancies metastatic to the spine has excellent durable 2-year local control rates. Preoperative embolization (PEm) is used as an adjunct to decrease operative blood loss for known hypervascular tumor histologies. Recent studies suggest potential benefits of PEm on local control and overall survival, but they involved heterogeneous tumor populations over time periods where systemic therapy was evolving rapidly. Therefore, we set out to determine the impact of PEm for metastatic spine tumors on a 2-year local control and overall survival in a histologically homogeneous cohort of patients with hypervascular tumor histologies.

METHODS

This was a single-center, retrospective chart review from 2011 to 2022 at a quaternary cancer center for all patients with renal cell carcinoma, hepatocellular carcinoma, or thyroid cancer diagnosed with spinal metastatic disease who underwent surgical treatment followed by SBRT with or without PEm.

RESULTS

Overall, 161 patients were included with 71 undergoing PEm (63 successful and 8 unsuccessful) and 90 not receiving PEm. The 8 who underwent angiogram but were not embolized were considered in the no PEm cohort. Between PEm and no PEm groups, there was no significant difference in age, sex, Eastern Cooperative Oncology Group, preoperative American Spinal Injury Association score, tumor histologies, number of adjacent segments involved, Spinal Instability Neoplastic Scale score, hospital length of stay, time from surgery to SBRT, radiation treatment dose (biological effective dose and equivalent dose in 2-gray fractions), or number of fractions ( P > .05 for all). The median overall survival was 18 months for both groups with no significant difference between PEm and no PEm ( P = .8). There was no significant difference in 12- and 24-month local control with rates of 94.8% and 91.7% for no PEm and 96.8% and 95.2% for the PEm group, respectively ( P = .7).

CONCLUSION

PEm demonstrated no impact on local control or overall survival in patients with hypervascular spine metastases undergoing separation surgery followed by SBRT.