Radiofrequency Ablation Combined With Polymethylmethacrylate For Treatment Of Paravertebral Metastasis In Rabbit Model Created By Transplantation Of VX2 Carcinoma:an Experimental Study

OBJECTIVE To investigate the killing effect of radiofrequency ablation (RFA) combined with PMMA on rabbit paravertebral VX2 tumor.METHOD 48 rabbit paravertebral metastasis models were successfully created by transplantation of VX2 carcinoma under CT guidance.48 models were randomly divided into four groups, which includes 12 rabbits in each group.0.5ml of PMMA was injected into the center of paravertebral tumor after radiofrequency ablation in group A,0.5ml of PMMA was only injected in group B. Radiofrequency ablation was only performed in group C,0.5ml of normal saline was injected in group D as the control group. The rabbits were sacrificed in 24 hours after operation. Four tissue samples were respectively selected in 5mm,10mm,15mm and 20mm away from the PMMA or the center of the tumor. TdT-mediated dUTP Nick-End Labeling (TUNEL) was used to detect apoptosis.RESULT Technique success rate was 91.7%(11/12) in 3 therapy groups and 100% in the control group. There was not significant difference in 4 groups. The tumor cellular morphologies were lost and the apoptosis rates couldn’t be detected in 10 mm away from the center of the tumor in group A and C. The apoptosis rate of VX2 tumor in 10mm,15mm and 20mm away from the PMMA in Group A was (69.48±1.27)%, (59.05±3.02)%, (21.03±2.20)% respectively. The apoptosis rate in the control group was (10.25±0.79)%. There were significant differences between group A and the control group. The apoptosis rate of VX2 tumor in 5mm,10mm,15mm and 20mm away from the PMMA in Group B were respectively (62.52±2.07)%, (45.07±3.14)%, (17.41±1.12)% and (11.15±0.97)%. There were significant differences between the group B and the control group expect in the 20mm observation point. The apoptosis rate in 10mm,15mm and 20mm away from the center of the tumor in group C was (67.74±3.33)%, (56.36±3.63)%, (20.71±1.11)% respectively. There were significant differences between the group C and group B or group D. There was not significant difference in each observation point between the group C and group A.CONCLUSION The apoptosis rates of paravertebral VX2 carcinoma whether after radiofrequency ablation or the PMMA injection were increased, but the former was stronger in the extent of tumor damage. Compared with only RFA, the killing range of VX2 carcinoma was not significantly increased after RFA combined with PMMA.