磁共振弥散加权成像参数ADC值与食管癌瘤体组织Sirtuin1蛋白表达的相关性

Correlation between ADC Value of MR-DWI and Expression Level of Sirtuin1 in Esophageal Carcinoma

[目的] 探讨磁共振弥散加权成像(MRI-DWI)参数表观弥散系数(ADC)值与食管癌组织Sirtuin1(SIRT1)蛋白表达的相关性,寻找预测食管癌辐射抵抗的生物靶标。[方法] 入组32例食管癌患者,收集所有患者治疗前肿瘤组织标本,行免疫组化检查,定量计算SIRT1蛋白表达情况。所有患者均接受根治性放疗,并于放疗前及放疗至第5次分割时接受两次MRI-DWI检查,利用脱机分析软件根据既定方法于食管癌瘤床区勾画感兴趣区域(ROI),得出相应ROI区域ADC值,取三次测量平均值为相应参数值。测量得出治疗前及放疗至第5次分割时ADC值,分别标记为pre-ADC、intra-ADC,通过前后两次ADC值计算得出ΔADC值。分析上述各ADC值与SIRT1蛋白表达的线性相关性。[结果] 32例患者中25例患者为影像学缓解反应组(完全缓解+部分缓解),7例患者为影像学稳定组(疾病稳定),缓解反应组和稳定组SIRT1表达水平分别为36.11%±4.66%和61.72%±4.08%(P=0.001)。治疗前32例食管癌瘤床区测量所得pre-ADC平均值为1.26±0.22(10-3mm^2/s);放疗至第5次分割时,食管癌瘤床区测量所得intra-ADC平均值为1.58±0.31(10-3mm^2/s);治疗前、放疗至第5次时ADC差值ΔADC为0.32±0.18(10-3mm2/s)。SIRT1表达水平与不同ADC值之间呈不同程度相关性(ΔADC:r=-0.967,P=0.002;intra-ADC:r=-0.746,P=0.002;pre-ADC:r=0.109,P=0.558)。[结论] MRI-DWI检查功能参数ADC值与SIRT1表达水平之间具有不同程度相关性,可能在预测食管癌辐射抵抗中发挥重要作用。

[Objective] To investigate the correlation between parameter apparent diffused coefficient(ADC) of magnetic resonance diffusion weighted imaging(MR-DWI) and the expression level of protein Sirtuin 1(SIRT1) in esophageal carcinoma patients.[Methods] Thirty two patients with pathologically diagnosed esophageal carcinoma undergoing radical chemoradiotherapy were enrolled. The expression of SIRT1 in cancer tissue before treatment were detected with immunohistochemical(IHC) method. All patients underwent esophageal MR-DWI examinations before treatment and after 5th fraction radiotherapy. The regions of interest(ROIs) were contoured in advance with off-line software according to the stipulated rules and the value of ADC in ROIs was generated automatically. The values of ADC at baseline and after 5th fraction RT were labeled as pre-ADC and intra-ADC,and ΔADC was calculated. Pearson correlation coefficient was acquired to estimate the correlation between ADC values and SIRT1 level. [Results] Among 32 patients,there were 25 cases of imaging response(complete response+partial response) and 7 cases of imaging non-response(stable disease). The expression levels of SIRT1 were 36.11%±4.66% in responders and 61.72%±4.08% in non-responders(P=0.001). The average pre-ADC,intra-ADC and ΔADC were 1.26±0.22(10^-3mm^2/s),1.58±0.31(10-3mm2/s)and 0.32±0.18(10^-3mm^2/s),respectively. The expression of SIRT1It was correlated with pre-ADC(r=0.109,P=0.558),intra-ADC(r=-0.746,P=0.002) and ΔADC(r=-0.967,P=0.002). [Conclusion] Parametric ADC of MRI-DWI is correlated with the expression of SIRT1 in tumor tissue and it may be used as a bio-marker to predict radiation response for esophageal carcinoma patients.