1.Dynamic contrast-enhanced MRI and diffusion weighted imaging in evaluating the early response to chemotherapy in non-small cell lung cancer
Xiaoping HE ; Zhongchang MIAO ; Guangjun BIAN ; Dehua WANG ; Shunbin JIANG ; Yongli FENG
Chinese Journal of Radiology 2016;50(10):746-751
Objective To investigate the value of dynamic contrast-enhanced(DCE)-MRI and DWI for the early assessment of curative effects in NSCLC. Methods Forty patients from September 2012 to September 2014 with NSCLC proven by pathology were examined with DCE-MRI and DWI, at one week before the first chemotherapy and one month after treatment. DCE parameters (MER, slope, WR) and ADC values of the tumors were calculated on the workstation. According to the changes of the tumor-size after treatment, all patients were divided into two groups: good response group and poor response group. Pretreatment parameters were compared between the two groups with independent-samples t test, and parameter changes before and after treatment were compared with paired-samples t Test. ROC curve of tumor response characteristic was analyzed. Pearson correlation coefficient was used to study the correlation between post-treatment parameter changes and tumor size reduction. Results Pretreatment ADC, MER and slope value were (1.15 ± 0.09) × 10-3 mm2/s, 1.13 ± 0.28, (3.76 ± 1.27)% in the good response group(15 patients), and were (1.34±0.33)×10-3mm2/s, 0.78±0.16, (2.63±0.58)%in poor response group(25 patients), respectively. There was significant difference between tumors in two groups(t=2.329, 3.152, 4.556,P=0.027, 0.032, 0.009), the lower ADC value and the higher MER/slope value was observed in the good response group. The change rates of ADC after one month treatment in the two groups were (20.43±6.40)%, (2.98±1.65)%(t=3.485,P=0.009), and slope change were (-61.80±19.21)%, (-30.80±11.16)%(t=3.280, P=0.020). Both the rising rate of ADC and decreasing rate of slope value were significant higher in good response group than the poor response group. The ROC curve was used to analyze the change rate of ADC and slope after tumors treatment, the area under the ROC curve in ADC was largest(Az=0.790), the diagnosis efficiency was highest. We found significant positive correlation between ADC, MER, slope change rate and tumor maximum diameter reduction rate after chemotherapy(r=0.637, 0.396, 0.532,P<0.05). Conclusions DCE parameters and ADC values possess important clinical value to evaluate the early effect of chemotherapy in NSCLC. ADC value is more sensitive to early lung cancer response.