Observation Of Radiosensitive Effect Of Sodium Glycididazole By Using¹⁸F-Fluorine-18-deoxyglucose Positron Emission Tomography/computed Tomography

SubjectTo evaluate the radiosensitizing effect of sodium glycididazole on the VX2lungtransplant tumor model during3-dimensional radiotherapy by usingfluorine-18-deoxyglucose （FDG） positron emission tomography/computed tomography（PET/CT）. To study the characteristics of¹⁸F-FDG PET/CT imaging in rabbit lung VX2transplant tumor during three-dimensional conformal radiotherapy, and to explore thevalue of¹⁸F-FDG PET/CT to assess the efficacy of tumor radiotherapy.MethodsTwenty-four tumor-bearing rabbits were established by percutaneous lung punctureunder CT guidance. Then evenly and randomly divided into4groups: radiotherapyalone group, CMNa plus radiation group, CMNa group and control group, six in eachgroup.¹⁸F-FDG PET/CT images were obtained to monitor the ratio tumor/muscle （T/M）of¹⁸F-FDG uptake before and after treatment. Tumor volume changes were alsoassessed. The expression of vascular endothelial growth factor in cancer organizationwas detect by immunohistochemical method. T/M percentage change （ΔM）, tumorvolume growth rate （ΔV） and VEGF assay rate （VEGF%）were analyzed.ResultsThe high rate of establishing a lung transplant tumor model by percutaneous lung puncture under CT guidance was88.6%（31/35）, and the positive rate of solitarypulmonary nodules was68.6%（24/35）. Tumor tissue has good uptake and retention of¹⁸F-FDG.100minutes after injection of¹⁸F-FDG, tumor tissue was clearly visualized.24h after treatment, the T/M ratio in CMNa plus radiation group and radiotherapy alonegroup is reduced, except the CMNa group and the control group. The T/M ratios ofradiotherapy group, CMNa plus radiation group, CMNa group and the control groupwere （6.54±1.17）、（5.09±1.16）、（13.67±1.55）、（14.33±1.46）. T/M percentage change（ΔM）in CMNa plus radiation group（34.3±12.4）is higher than radiotherapy alone group（17.6±13.3）,the difference between groups was statistically significant （P <0.05）. Thelung tumor volume is all have growth before treatment in four groups, the ΔV in CMNaplus radiation group are minimum,compare with the rest of the three groups, it werestatistically significant difference （P <0.05）. Histopathological observation revealedthat the vast majority of tumor cells had died in the CMNa plus radiation group andradiotherapy alone group. The VEGF%in CMNa plus radiation group are minimum,VEGF%are positively related to T/M and V in each group （r=0.93,0.76, P <0.01）.Conclusion¹⁸F-FDG PET/CT imaging in VX2tumor-bearing rabbits after three-dimensionalconformal radiotherapy, T/M ratio significantly reduced in a short time while tumorvolume was not reduced, combined with the pathological results it suggested that¹⁸F-FDG PET/CT imaging could evaluate the early reaction of radiotherapy beforemorphology changes.CMNa could increase the sensitivity of three dimensional conformal radiotherapy inVX2lung transplant tumor and significantly inhibit tumor angiogenesis.¹⁸F-FDGPET/CT could reflect tumor hypoxia status and angiogenesis in a certain extent, whichis more prescriptive than tumor volume. That could be used to monitor early therapeutic efficacy and develop new sensitizer.