| There are three parts in our study.Part1:Percutaneous Osteoplasty as a Treatment for Painful Osteoblastic Metastatic LesionsOBJECTIVE:To investigate the feasibility and clinical efficacy of percutaneous osteooplasty (POP) for painful osteoblastic metastatic lesion.METHODS:six patients with painful blastic metastatic lesions were treated by POP under fluoroscopic or CT guidance. Patients were asked to quantify the pain on a visual analogue scale of 1-10, with 10 indicating maximum pain, before treatment and the week after POP. The fluoroscopy time used for puncture and the amount of bone cement used for POP was noted.RESULTS:All six patients treated in our institution showed immediate pain alleviation after the procedure. No clinically significant complications or unwanted side effects of the cement injection occurred. The average duration of fluoroscopy for the 4 patients with spinal lesions during puncture is 10.3±1.1min. The average amount of bone cement used for the group of four patients was 2.9±0.5ml, and the fewest amount used was 2.2ml.CONCLUSION:The analgesic effect of POP in treating patients with osteoblastic lesions is well and the treatment is safe. It is possible to perform POP as a treatment for patients with osteoblastic lesions, provided that the puncture skill and the appropriate amount of bone cement could be taken into consideration.Part 2:An Intravertebral Tumor Model in Rabbits by Transplantation of VX2 Carcinoma via Percutaneous Puncture under CT GuidanceOBJECTIVE:The purpose of the present study was to establish an animal model of metastatic spinal tumors by transplanting VX2 carcinoma into a lumbar vertebral body with computed tomographic [CT] guided percutaneous puncture technique and to analyze the onset of the paraplegia, radiographic changes (magnetic resonance imaging [MRI] and CT scans), and histopathological findings after intraosseous transplantation of VX2 carcinoma pieces into the lumbar vertebrae of rabbits.METHODS:New Zealand white rabbits (n= 32) were transplanted with VX2 carcinoma in the lumbar vertebral body with CT guided percutaneous puncture technique. Lower extremity motor function was assessed twice daily. MRI(T2-weighted and Tl-weighted +gadolinium) and CT scans were acquired at postoperative day (POD) 14,21,28 and at the onset of paraparesis.When the vertebral tumors were detected by CT and MRI scans at POD 21 or 28, two of these animals without paraparesis were killed randomly and the spines were dissected respectively.After demineralization, the hematoxylin and eosin cross sections were obtained.The other animals were sacrificed and the spines were dissected at the onset of paraparesis.By the termination of the experiment on POD 90, the remaining animals without paraparesis were sacrificed after CT and MRI scans, and the actual conditions of the tumor were evaluated based on the axial localization from the inoculation position of the spinal tumor. The histological studies were also performed.RESULTS:The success rate of vertebral tumor in the experiment were 90.6%(29/32). Paravertebral tumor was revealed in one rabbit and no tumor was showed in two rabbits. Before the onset of paraparesis, the CT and MRI scans could reveal gross tumor. MRI scans revealed vertebral tumor in one rabbit without paraparesis on POD 14. MRI and CT scans revealed vertebral tumor in 21 rabbits on POD 21, of whom 19rabbits were no paraparesis.The vertebral tumors were detected in another 7rabbits by MRI and CT scans on POD 28, including 6 rabbits without paraparesis. The earliest day of paraparesis was POD 19, the latest was POD 36, and the mean onset of paraparesis was 26.4±4.2 days. CT scans demonstrated an osteolytic tumor centered in the vertebral body, and MRI scans showed epidural tumor arising from the body and compressing the spinal cord. Histopathological examination confirmed carcinoma arising from the body and extending into the canal, with widespread osteolytic activity.CONCLUSION:A novel intraosseous intravertebral tumor model in rabbits confirmed by CT, MRI and histopathology, was established via percutaneous puncture under CT guidance. The method was easy and feasible with very high success rate.The vertebral tumors could be revealed by CT and MRI in most of rabbits from POD 21.Part 3:The Cytotoxic Effect of Bone Cement on Vertebral Tumor of Rabbit after Percutaneous VertebroplastyOBJECTIVE:To investigate cytotoxic effect of bone cement on vertebral Tumor in-vivo after Percutaneous VertebroplastyMETHODS:Vertebral tumor model of rabbit was randomly divided into 3 groups: PMMA Group (n=10):PMMA 0.3ml was injected into the tumor, CPC group (n=10): CPC 0.3 ml was injected into the tumor, Control group (n=10):physiological saline 0.3 ml was injected into the tumor. The groups A and B were therapy groups. The group C was control group (pseudo-therapy group). PET-CT was performed on all the rabbits before the PVP. Then the value of SUVmax and SUVmean of each tumor vertebra and normal L, vertebra of itself was measured. 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 SUVmean of each tumor vertebra and normal L1 vertebra of itself was measured again. Then the rabbits were executed and the tissues of tumor were collected for pathological examination. The morphological change and necrosis of tumor cells near and away from the bone cements were observed by HE stain. Terminal deoxvnucleotidvl transferase mediated nick end labeling (TUNEL) and immunohistochemisty were used to detect apoptosis, Bcl-2 and Bax protein expression in the tumor cell, which was near and away from the bone cements. Then the result of TUNEL apoptosis and Bcl-2, Bax expression measurement in the tumor cells were analyzed by VIDAS. And the mean absorbance was calculated. The value of SUVmax and SUVmean of each tumor vertebra and normal L, vertebra of itself before and after PVP was analyzed by Repeated Measures Analysis of Variance. The value of SUVmax and SUVmean of each tumor vertebra in different groups and different time points was analyzed by Analysis of Factorial. The TUNEL apoptosis, Bcl-2, Bax protein expression in the tumor cells and the mean absorbance in different groups and different time points and different place were analyzed by Analysis of Factorial.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 the different time points after the 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. 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 live tumor cells could be found in necrosis tissues. The number of tumor cells near the PMMA bone cement increased in 4 day after treatment compared with lday after treatment. While the tumor cells away from the PMMA bone cement proliferated actively in 4 day after treatment. Significant necrosis of tumor cells was not found in the other two groups in different time. TUNEL apoptosis examine showed that the apoptosis index (AI) among different groups, time points and place had statistical difference (P<0.05). The apoptosis of tumor cells was reduced in the order of PMMA, CPC and control groups. The apoptosis of tumor cells near the PMMA cement was significant in different time points after treatment, especially in 1 day after treatment. The number of tumor cells with apoptosis was reduced in 4d after treatment. The apoptosis of partial tumor cells near the CPC cement was visible in lday after treatment; however few tumor cells with apoptosis were found 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. The Bcl-2 protein decreased in the order of control group, CPC group, and PMMA group. However, the Bax protein increased in the order of control group, CPC group, and PMMA group.CONCLUSION:PMMA cement could significantly result in necrosis of the vertebral tumor cells in-vivo and induce apoptosis of tumor cells. The cytotoxic effect of tumor cells near the PMMA cement was more significant than that away from the PMMA cement. The cytotoxic 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. Bcl-2 and Bax expression may play an important role in the apoptosis of tumor cells induced by bone cement... |
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