Objective This paper studies on feasibility of low dose CT scanning in lung cancer patients simulated localisation.Methods 62 patients cases of lung cancer are selected.Scan parameter:scan twice by 20/100 mA,the other parameter remain unchanged as voltage of 120 kV,thickness of 5 mm,pitch of 1:1 and scan time of 1 s.After scan,picture quality was evaluated according to excellent,good,bad under different condition.Volume of target was determined by treatment planning system.Data such as dose index value of single helical scan,z-axis scan range,dose length product value and etc.are recorded in order to evaluate radiation dose of patients.Picture quality and the difference of radiation dose were statistically analyzed using Fisher's and pair t-test.Results Picture quality of low dose scanning was a little bit lower than that of normal dose,however,picture quality difference of difference dose scanning was statistically meaningless (number of patients according to excellent,good,bad were 46,13,3 and 50,11,1,P =0.541).There is no obvious difference of target volume under different dose scanning in the same (36.78 cm3,40.35 cm3,t =2.57,P =0.189).Radiation dose of low dose scanning group is far less than that of high dose scanning group and the difference is obvious (133.05 mGy,941.25 mGy,t =-41.24,P =0.000).Conclusions Low dose scanning of 20 mA current during CT simulated localisation tremendously reduces harm that may happen to patients during CT scan,while tumor target delineation and scanned picture quality is guaranteed.

Objective: To detect the expression of NRAGE protein in esophageal squamous cell carcinoma and investigate the relationship between NRAGE and therapeutic effect of radiotherapy. Methods: The expression level of NRAGE in 44 patients with esophageal squamous cell carcinoma was evaluated by immunohistochemistry and statistically analyzed along with clinical data by using multivariate analysis using Cox regression model. Results: The overall expression level of NRAGE protein in esophageal squamous cell carcinoma (P=0.025) and the expression level of NRAGE nuclear protein (P=0.008) were negatively correlated with short-term efficacy. In terms of the overall expression level of NRAGE protein, the 3-year survival rates in the strongly positive group and the positive weakly positive group were 16% and 36%(P=0.198). As for the expression of NRAGE nuclear protein, the 3-year survival rates in the strongly positive group and the positive+ weakly positive group were 0% and 41%(P<0.001). Multivariate analysis using Cox regression model demonstrated that as for the expression of NRAGE nuclear protein, the risk of death in the strongly positive group was significantly higher than those in the positive+ weakly positive group (P=0.002). Conclusion The overall expression level of NRAGE protein in the esophageal cancer is negatively correlated with the short-term efficacy of radiotherapy, whereas it is not correlated with long-term survival rate. The strongly positive expression level of NRAGE nuclear protein is negatively correlated with the short-term efficacy of radiotherapy and the long-term survival rate, prompting that NRAGE may be a molecular indicator for predicting radiation resistance and even the efficacy of radiotherapy for esophageal squamous cell carcinoma