A new endoscopic ultrasonography image processing method to evaluate the prognosis for pancreatic cancer treated with interstitial brachytherapy

AIM:To develop a fuzzy classification method to score the texture features of pancreatic cancer in endoscopic ultrasonography(EUS)images and evaluate its utility in making prognosis judgments for patients with unresectable pancreatic cancer treated by EUS-guided interstitial brachytherapy.METHODS:EUS images from our retrospective database were analyzed.The regions of interest were drawn,and texture features were extracted,selected,and scored with a fuzzy classification method using a C++program.Then,patients with unresectable pancreatic cancer were enrolled to receive EUS-guided iodine 125 radioactive seed implantation.Their fuzzy classification scores,tumor volumes,and carbohydrate antigen 199(CA199)levels before and after the brachytherapy were recorded.The association between the changes in these parameters and overall survival was analyzed statistically.RESULTS:EUS images of 153 patients with pancreatic cancer and 63 non-cancer patients were analyzed.A total of 25 consecutive patients were enrolled,and they tolerated the brachytherapy well without any complications.There was a correlation between the change in the fuzzy classification score and overall survival(Spearman test,r=0.616,P=0.001),whereas no correlation was found to be significant between the change in tumor volume(P=0.663),CA199 level(P=0.659),and overall survival.There were 15 patients with a decrease in their fuzzy classification score after brachytherapy,whereas the fuzzy classification score increased in another 10 patients.There was a significant difference in overall survival between the two groups(67 d vs 151 d,P=0.001),but not in the change of tumor volume and CA199 level.CONCLUSION:Using the fuzzy classification method to analyze EUS images of pancreatic cancer is feasible,and the method can be used to make prognosis judgments for patients with unresectable pancreatic cancer treated by interstitial brachytherapy.

Comparison of Abbott and Da-an real-time PCR for quantitating serum HBV DNA

AIM: To compare the performance of the Da-an realtime hepatitis B virus(HBV) DNA assay and Abbott RealTime HBV assay. METHODS: HBV DNA standards as well as a total of 180 clinical serum samples from patients with chronic hepatitis B were measured using the Abbott and Daan real-time polymerase chain reaction(PCR) assays. Correlation and Bland-Altman plot analysis was used to compare the performance of the Abbott and Daan assays. The HBV DNA levels were logarithmically transformed for analysis. All statistical analyses were performed using SPSS for Windows version 18.0. Thecorrelation between the two assays was analyzed by Pearson's correlation and linear regression. The BlandAltman plots were used for the analysis of agreement between the two assays. A P value of < 0.05 was considered statistically significant.RESULTS: The HBV DNA values measured by the Abbott or Da-an assay were significantly correlated with the expected values of HBV DNA standards(r = 0.999, for Abbott; r = 0.987, for Da-an, P < 0.001). A BlandAltman plot showed good agreement between these two assays in detecting HBV DNA standards. Among the 180 clinical serum samples, 126 were quantifiable by both assays. Fifty-two samples were detectable by the Abbott assay but below the detection limit of the Da-an assay. Moreover, HBV DNA levels measured by the Abbott assay were significantly higher than those of the Da-an assay(6.23 ± 1.76 log IU/mL vs 5.46 ± 1.55 log IU/mL, P < 0.001). A positive correlation was observed between HBV DNA concentrations determined by the two assays in 126 paired samples(r = 0.648, P < 0.001). One hundred and fifteen of 126(91.3%) specimens tested with both assays were within mean difference ± 1.96 SD of HBV DNA levels.CONCLUSION: The Da-an assay presented lower sensitivity and a narrower linear range as compared to the Abbott assay, suggesting the need to be improved.

Corrosion resistance of steel materials in LiCl-KCl melts

The corrosion behaviors of 304SS, 316LSS, and Q235A in LiCl-KCl melts were investigated at 450℃ by Tafel curves and elec- trochemical impedance spectroscopy （EIS）. 316LSS shows the best corrosion resistance behaviors among the three materials, including the most positive corrosion potential and the smallest corrosion current from the Tafel curves and the largest electron transfer resistance from the Nyquist plots. The results are in good agreement with the weight losses in the static corrosion experiments for 45 h. This may be attributed to the better corrosion resistance of Mo and Ni existing as alloy elements in 316LSS, which exhibit the lower corrosion current densities and more positive corrosion potentials than 316LSS in the same melts.

A Non-invasive Method of Fetal Growth Evaluation

The fetal weight vs. the gestational age has great significance for fetal growth evaluation in clinic especially in the judgement of IUGR. In this paper, the quantification theory and its application for estimation of the gestational age and fetal weight are reported.It is the first time that the theory is applied in this field. The estimation error.of gestational age is less than one week and that of fetal weight is less than 130g.