| Background and purpose: The morbidity and mortality of lung cancer has become the first in the malignant tumors.Although lung cancer patients at the early stage can choose surgery, because of the limitation of level of screening and diagnosis, most of the patients with lung cancer with clinical symptoms are in ? ~ ? period, lose the operation chance and need to select the chemotherapy. In our country, 5-year survival rate is only 15.6% for patients with lung cancer, because nearly 75% of patients found in clinic that is already in the middle-late stages of the disease. Therefore, to reduce the mortality of lung cancer must improve lung cancer screening technology, making the lung cancer patients at the early stage can get timely and accurate diagnosis. At the same time, for many lung cancer patients at middle-late stage, accurate assessment of the curative effect for lung cancer chemotherapy could help clinical doctors adjust the treatment plan timely and reasonably improve curative effect, and realize the real individual accurate treatment.At present, the commonly used screening and evaluation of lung cancer clinical curative effect of chemotherapy is chest spiral CT imaging examination, etc. These ways are all only based on morphology. Examination and treatment in patients with multiple times during a short time leads to ray cumulative damage. DWI imaging physics is based on the water molecules heat movement or Brownian motion. In living organisms, water molecules of different organizational structures or the same organization under different pathological states within the dispersion ability is different.This is the biological basis of DWI. The dispersion ability of water molecules is the main factors influencing the DWI imaging, usually expressed in the ADC. For different pathological states ADC values achieved on quantitative analysis DWI, provide quantitative analysis of diagnosis information, so as to more effectively reflect the changes in the microstructure of the organization.DWI has high clinical value in identifying benign and malignant lung lesions. Lung cancer of different pathological types and proliferation degree is an important factor to decide treatment and prognosis, so research of the ADC values and lung cancer of different pathological types and the relationship between the degree of proliferation and ADC values has great clinical significance and research value. In addition, effective anti-tumor treatment can lead to dissolve the tumor cell, rupture, wider intercellular space, so that diffuse ability of water molecules enhancs and ADC values increase. Therefore, DWI and ADC values can not only evaluate the effect from the lung cancer treatment by morphology, but also reflect histologic treatment curative effect by microscopic aspect. The current clinical use of DWI examination in lung cancer chemotherapy curative effect evaluation research is very limited, and still need to further discuss the application value. Therefore, the purpose of this study is to investigate the ADC values in distinguishing between lung cancer of different pathological types, its role and the relationship between the different degree of proliferation of lung cancer, its significance in the prediction of chemotherapy efficacy and its combination with serological tumor markers for diagnosis of lung cancer of different histopathologic types of diagnostic value. Further studying the application of DWI technique can evaluate lung cancer chemotherapy curative effect, by comparing with the traditional spiral CT,could shed light on the value and significance of DWI examination and ADC values in lung cancer chemotherapy curative effect evaluation. Methods and results: 1.The baseline ADC values help to distinguish lung cancer histopathological types.By using two independent sample t-test and one way analysis of variance 90 cases of different pathological types of lung cancer patients with baseline ADC values results showed that the difference between NSCLC and SCLC baseline ADC values was statistically significant(P = 0.000). The difference baseline ADC values between adenocarcinoma and SCLC was statistically significant(P = 0.000).The difference baseline ADC values between squamous cell carcinomas and SCLC was statistically significant(P = 0.002). The difference of ADC values between adenocarcinoma and squamous cell carcinomas was not statistical different(P = 0.646). ROC analysis showed that ADC values applied to distinguish between NSCLC and SCLC had certain clinical significance(AUC = 0.752). Consequently baseline ADC values is helpful to distinguish lung cancer histopathological types. 2. The baseline ADC values can help to judge the proliferation degree of lung cancer.Using Pearson correlation analysis the relationship between with baseline ADC values and proliferation index of Ki- 67 in 70 cases of lung cancer patients showed they had relevant relations(r =-0.408,P=0.000).The lower the ADC values, the higher the tumor proliferation index, ADC value in determining tumor proliferation degree has a certain significance. 3. The combined use of ADC values and serum tumor markers can improve the diagnostic ability to distinguish between NSCLC and SCLC.Using ROC curve and Logistic regression analysis results showed that: AUC for separate application of CEA and ADC values in the diagnosis of NSCLC were 0.619 and 0.741, but AUC of combined these two indicators was 0.772. For separate application of SCC and ADC values in the diagnosis of NSCLC AUC were 0.766 and 0.766, but AUC of combined these two indicators was 0.821. For separate application NSE and ADC values in the diagnosis of SCLC AUC were 0.589 and 0.752, but AUC of combined these two indicators was 0.761. The combined use of ADC values and serum tumor markers can improve the diagnostic ability to distinguish between NSCLC and SCLC. 4. The baseline ADC values can be used to help predict curative effect of tumor chemotherapy.Using the correlation analysis between the two variables and calculating the Pearson correlation coefficient analysis showed: there was correlation between baseline ADC values and using CT evaluation the change rate of maximum diameter of lung cancer before and after chemotherapy in 30 cases of lung cancer patients. Baseline ADC values can be used to help predict of curative effect tumor chemotherapy. Treatment effect of tumors with the higher ADC values is not as good as the lower ADC values tumor. 5. DWI examination can be used to evaluate lung cancer chemotherapy curative effect.By using two independent sample t-test analysis of 30 patients with lung cancer, there was no statistical difference between PR and SD group according to baseline ADC values before and after treatment(P>0.05). But the change rate of combined maximum diameter by the CT measurement, the change rate of tumor combined maximum diameter by the DWI/T2WI measurement, these rates had statistical differences between PR and SD groups(P<0.05). It indicated that there was the same in evaluating curative effect of chemotherapy between DWI examination and chest CT examination. We respectively compared the differences of tumor combined maximum diameters before and after chemotherapy by CT and T2WI. Results showed that there was no statistical difference(P>0.05). It suggested that there was no difference in assessing lung lesions size between DWI/T2WI examination and chest CT examination. DWI/T2WI can evaluate the effect of lung cancer chemotherapy on morphology. By further analyzing,there was no statistical difference in the combined largest diameter by CT before and after treatment(P>0.05).However, there was statistical difference in the combined largest diameter by DWI T2WI before and after treatment(P<0.05). It confirm that DWI/T2WI measured changes in morphology index can be more sensitive to evaluate the changes after chemotherapy in lung cancer. 6. ADC values can be used to evaluate curative effect of lung cancer chemotherapy.By using two independent sample t-test analysis of 30 patients with lung cancer, there was no statistical difference between PR and SD group according to baseline ADC values before and after treatment(P > 0.05). But ADC values change quantity and rate by the DWI measured have statistical differences between PR and SD group(P< 0.05). Furthermore, there was a positive correlation between the change rate of ADC value and CT measured combined aximal diameter of tumor(r=0.523,P=0.003). It confirmed that ADC values could be used not only in the morphological evaluation but also as a biological indicator to evaluate the curative effect of tissue structure change after chemotherapy. To assess the curative effect of chemotherapy by the change rate of ADC values before and after chemotherapy,the area under the curve is 0.804(P< 0.05) using ROC curve analysis. It shows that ADC values have diagnostic performance to evaluate curative effect of lung cancer chemotherapy. The change rate of ADC values can be used as an index of evaluating the effect of lung cancer chemotherapy. This analysis measured that is no statistical difference in CT measured combined aximal diameter of tumor between before and after treatment(P > 0.05). However, there is statistically significant in the two groups before and after the treatment on DWI measured combined aximal diameter of tumor and ADC values(P < 0.05). It confirms that ADC values can be more sensitive to reflect the lung cancer after chemotherapy not only in morphology but also in structural of the organization. Conclusion:Taken together, DWI examination and ADC values can help to determine lung cancer of different histological pathology types and proliferation degree. Its combination with the serum tumor markers(CEA, SCC, NSE) can improve the ability of diagnosis for histological pathology types of lung cancer. Baseline ADC values can predict curative effect of lung cancer chemotherapy. DWI examination can be used to evaluate curative effect of lung cancer chemotherapy. As well ADC values can be more sensitive to reflect the curative effect of lung cancer chemotherapy. |
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