Objective To evaluate the efficacy and safety of percutaneous radiofrequency ablation combined with immunotherapy in the treatment of hepatocellular carcinoma .Methods A total of 124 patients with liver cancer were randomly divided into the two groups .60 cases in the control group were given immunity treatment alone ,while 64 cases in the observation group were treated by percutaneous radiofrequency ablation combined with immune therapy . The middle and long term curative effect of two groups was observed .Results After treatment,the tumor diameter, serum alpha fetoprotein (AFP) and carcino-embryonic antigen (CEA) levels in the two groups were significantly decreased(t=4.867,P=0.005;t=5.175,P=0.004;t=3.155,P=0.025;t=4.845,P=0.005;t=4.031,P=0.010;t=2.668,P=0.044),but the declining degree of the observation group was better than the control group (t=4.119,P=0.009;t=3.621,P=0.015;t=3.492,P=0.017).The total effective rates and disease control rates of the observation group were 53.1%,78.1%,which were significantly higher than 28.3%,46.7%in the control group (χ2 =11.290,P=0.010;χ2 =21.290,P=0.000).The 1-year,3-year,5-year survival rates of the observation group were 60.9%,31.3%,12.5%,those of the control group were 21.7%,5.0%,0.0%,the middle and long term sur-vival rates of the observation group were significantly higher than the control group (χ2 =21.935,P=0.000;χ2 =56.452,P=0.000;χ2 =40.516,P=0.000).No statistically significant differences in the CD 4+,CD8+,CD4+/CD8+, IL-12 and other indicators between the two groups before treatment ,but these indicators in the observation group were significantly improved after treatment (t =4.515,P =0.006;t =10.014,P =0.000;t =5.217,P =0.003). Conclusion Combination of percutaneous radiofrequency ablation and immunotherapy in the treatment of hepatocell-lular carcinoma has exact effect and with advantages of less adverse reaction , good safety , which can significantly improve the quality of life and survival rate of patients ,it has good clinical application value .

ObjectiveTo study the CT values of certain phantoms scanned by various CT scanners with dissimilar parameters.Methods The CT values of tissue equivalent inserts was measured in the TM164 and CIRS-062 phantom scanned by TOSHIBA AQUILIONTM,SIEMENS SOMATOMTMSENSATIONTM 64 and SIEMENS SOMATOMTM SENSATIONTM OPEN with different voltages,currents and slice thicknesses and then the corresponding CT-to-density curves was compared. Results There are no significant differences of CT values with various currents and slice thicknesses and also for low atom number materials scanned by different scanners with various tube voltages.The CT values of high atom number materials have obvious differences scanned with tube voltage,the maximum is about 400 HU.There are also significant differences between CT-density curves of two phantoms in the range from soft tissues to dense bone,the maximum is up to 500 HU.ConclusionsCT-density curves were highly affected by materials of phantoms,scanners and tube voltages.It is necessary to measure the curve with a comfortable phantom and certain scanner to assure the accuracy for dose calculation for treatment planning system.