The Anti-tumor Effect Of Different Bone Cements On Vertebral Tumor During Percutaneous Vertebroplasty: An Experimental Study In Rabbits

Object: To investigate anti-tumor effect of two kinds of bone cement (PMMA and CPC) on vertebral tumor of rabbit during percutaneous vertebroplasty (PVP).Materials and methods: 1. Establishing vertebral tumor models: New Zealand white rabbits were transplanted with VX2 carcinoma in the lumbar vertebral body with CT guiding percutaneous puncture technique. Vertebral tumor models were checked after 3 weeks by PET-CT. Then the value of SUVmax and SUVmea of each tumor vertebra and normal L1 vertebra of itself was measured. 2. Experimental grouping and treatment method: Vertebral tumor models were randomly divided into 3 groups. Each group consisted of 10 rabbits. With CT guiding percutaneous puncture technique, 0.3ml PMMA (group A), CPC (group B) or physiological saline (group C) was respectively injected into the tumor. The groups A and B were therapy groups. The group C was control group (pseudo-therapy group). Five rabbits were randomly selected to be checked again by PET-CT in 1d and 4d after PVP respectively in each group. And the value of SUVmax and SUVmea of each tumor vertebra and normal L1 vertebra of itself was measured. Then the rabbits were executed and the tissues of tumor were collected for pathological examination. 3. Observation index:â—‹1 The variety of the value of SUV: The value of SUVmax and SUVmea of each tumor vertebra and normal L1 vertebra of itself in different group and different time was measured and recorded.â—‹2 HE stain results: The morphological change and necrosis of tumor cells near and away from the bone cements were observed by HE stain.â—‹3 The result of TUNEL apoptosis measurement: TUNEL apoptosis measurement was used to detect apoptosis of tumor cells near and away from the bone cements. And the apoptosis index (AI) was calculated. Then the result of TUNEL apoptosis measurement was analyzed by VIDAS. And the mean absorbance was calculated. 4. Statistic methods: The value of SUVmax and SUVmea of each tumor vertebra and normal L1 vertebra of itself before and after PVP was analyzed by Repeated Measures Analysis of Variance. The value of SUVmax and SUVmea of each tumor vertebra in different group and different time was analyzed by Analysis of Factorial. The AI and the mean absorbance in different group and different time and different place were analyzed by Analysis of Factorial.Results: 1.PET-CT results: The value of the SUV of the tumor vertebra in the PMMA group had statistical difference (P<0.05) among before, 1 day and 4 day after treatment. The value of the SUV of the tumor vertebra dropped markedly, especially in 1 day after the PMMA cement injected. But that between the other two groups hadn't statistical difference. In different time after treatment, the value of the SUV of the tumor vertebra in the PMMA group compared the other two groups had statistical difference (P<0.05). But that between the other two groups hadn't statistical difference. 2.HE stain results suggested that there was typical nuclei concentration,nuclei cleavage,nuclei dissolution and necrosis of tumor cells near the PMMA bone cement in 1 day after treatment. Few tumor cells could be found in necrosis tissues, especially away from the PMMA cement. The tumor cells near the PMMA bone cement significantly proliferated in 4 day after treatment. While the tumor cells away from the PMMA bone cement proliferated actively. Significant necrosis of tumor cells was not found in the other two groups in different time.3. TUNEL apoptosis examine showed that the apoptosis index (AI) among different group, time and place had statistical difference (P<0.05). The apoptosis of tumor cells in the PMMA, CPC and control group was reduced in turn. The apoptosis of tumor cells near the PMMA cement was significant in different time after treatment, especially in 1 day after treatment. The apoptosis of partial tumor cells away from the PMMA cement could be seen. The apoptosis of tumor cells was reduced in 4d after treatment. The apoptosis of partial tumor cells near the CPC cement was visible in 1d after treatment; however the apoptosis of tumor cells decreased away from the CPC cement. The apoptosis of tumor cells of the CPC group was not obvious in 4d after treatment. The apoptosis of few tumor cells of the physiological saline group was visible. The results of absorbance were similar with that of AI.Conclusion: PMMA cement could significantly result in necrosis of the vertebral tumor cells in-vivo and induce apoptosis of tumor cells. The anti-tumor effect of tumor cells near the PMMA cement was more significant than that away from the PMMA cement. The anti-tumor effect gradually decreased with the time after PVP. CPC couldn't directly result in necrosis of the vertebral tumor cells in-vivo, but could slightly induce apoptosis of tumor cells.