355 - Prophylactic Cement Augmentation for Patients at High Risk for Developing Vertebral Body Compression Fracture Following Spine Stereotactic Radiosurgery: A Randomized Phase II Clinical Trial

09:15am - 09:25am ET

Room 160

Presenter(s)

Amol Ghia, MD - MD Anderson Cancer Center, Houston, TX

A. J. Ghia¹, B. Amini², J. Li¹, T. Beckham¹, C. Wang¹, D. N. Yeboa¹, D. Koyyalagunta³, T. M. Briere³, M. F. F. McAleer¹, M. C. Tom¹, B. De¹, S. Perni¹, H. Y. Lin⁴, L. D. Rhines⁵, R. Sheth⁶, and C. Tatsui⁵; ¹Department of CNS Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, ²Department of Musculoskeletal Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX, ³University of Texas, MD Anderson Cancer Center, Houston, TX, ⁴Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, ⁵Department of Neurosurgery, The University of Texas MD Anderson Cancer Center, Houston, TX, ⁶Department of Interventional Radiology, The University of Texas MD Anderson Cancer Center, Houston, TX

Purpose/Objective(s): Vertebral compression fracture (VCF) is a potential complication following spine stereotactic radiosurgery (SSRS), possibly leading to structural instability and pain. While prophylactic cement augmentation is hypothesized to mitigate this risk, prospective randomized data remain limited. We conducted a Phase II randomized trial to test the hypothesis that prophylactic cement augmentation at the time of SSRS reduces the incidence of new or progressive VCF at 3 months compared with SSRS alone.

Materials/Methods: Patients with spinal metastases deemed at high risk for VCF were randomized to receive single-fraction SSRS alone or SSRS followed by prophylactic cement augmentation. The primary endpoint was the incidence of new or progressive VCF at 3 months, analyzed on an intent-to-treat (ITT) basis. Secondary endpoints included time to local failure, overall survival (OS), salvage stabilization, and treatment-related toxicity. Cumulative incidence of VCF and local failure were evaluated using Fine and Gray’s competing risk models, with death treated as a competing risk.

Results: A total of 87 patients were enrolled. At the time of preliminary analysis, 60 patients were included in the intent-to-treat (ITT) cohort (35 in the SSRS alone arm and 25 in the SSRS + cement arm). The cumulative incidence of VCF did not significantly differ between the SSRS alone and SSRS + cement arms (p=0.38). Similarly, no significant differences were observed between the treatment arms for the cumulative incidence of local failure (p=0.73) or overall survival (p=0.57). For salvage procedures, 4 out of 35 patients (11%) in the SSRS alone arm subsequently crossed over to undergo salvage cement augmentation. Treatment was generally well tolerated. Grade 3 adverse events occurred in 1 patient (possibly related) in the SSRS alone arm and 4 patients (3 unrelated, 1 unlikely related) in the cement augmentation arm. No Grade 4 or 5 adverse events were reported.

Conclusion: Preliminary intent-to-treat analyses of this randomized Phase II trial demonstrate that prophylactic cement augmentation did not significantly reduce the overall incidence of radiographic VCF or local failure compared to SSRS alone, though 11% of patients treated with SSRS alone required subsequent salvage stabilization. Further evaluations of clinical pain failure and fracture magnitude are ongoing to identify whether specific high-risk patient subsets may derive structural or symptomatic benefit from prophylactic stabilization.