1:45 PM, Abstract No. 32 - The anti-tumor effect of polymethylmethacrylate cement on vertebral tumor of rabbit after percutaneous vertebroplasty

Abstract

Percutaneous vertebroplasty (PVP) has been commonly used for the treatment of vertebral compression fractures secondary to metastasis and has been shown to achieve excellent pain relief immediately after the PVP. However, the mechanism by which PVP treats vertebral lesions remains controversial, and it is speculated that mechanical and/or anti-tumor effects of polymethylmethacrylate (PMMA) cement might be responsible for the pain relief. The purpose of this study is to investigate the anti-tumor effect of bone cement on vertebral tumor in-vivo after PVP. Twenty New Zealand white rabbits with lumbar vertebral tumor, established by percutaneous puncturing transplant of VX2 carcinoma, were randomly and equally divided into the study group and the control group with 10 rabbits in each group. PVP with injection of 0.3 ml PMMA cement was carried out on the rabbits of the study group while the procedure with injection of 0.3 ml physiological saline was employed with the rabbits of the control group. PET/CT was performed on all the rabbits before the PVP. The stand uptake value (SUV) of each vertebral tumor was then measured. Five rabbits were randomly selected at 1d and 4d after the cement or saline injection respectively in each group. PET/CT was performed again on each rabbit. The animals were then executed and the tissues of the tumors were collected for pathological examination. Before PVP, the difference in SUV of the vertebral tumors between the two groups was of no statistical significance. In the study group, the SUV of the vertebral tumor was dropped markedly after the PMMA cement injecting. However, there is no significant difference in the SUV of the vertebral tumors between the pre- and post-procedure in the control group. Pathological results showed that there were typical nuclei concentration, nuclei dissolution and necrosis of tumor cells near the cement, on the contrary, this was not observed in the control group. PMMA cement has a significant anti-tumor effect on the vertebral tumor in-vivo after the PVP, and this could be at least one of the mechanisms by which PVP treats malignant vertebral lesions.