CT结合DWMRI评价非小细胞肺癌放化疗疗效研究

Application of CT combined with diffusion-weighted magnetic resonance imaging for evaluating the therapeutic effect of lung cancer

目的当前,肺癌非手术治疗后疗效评价主要通过观察肿瘤体积大小的变化来进行判断,但对于肿瘤细胞功能状态的改变方面存在一定局限性。本研究旨在探讨CT结合磁共振弥散加权成像(diffusion-weighted magnetic resonance imaging,DWI)综合评价非小细胞肺癌放化疗疗效新标准的应用研究。方法选取2010-09-01-2014-09-30河北医科大学收治接受三维放疗的非小细胞肺癌患者48例,处方剂量58~66Gy,单次2~2.2Gy,同期1~2个周期化疗。放疗前、放疗末行CT扫描及DWI检查,应用CT标准、DWI高信号表达情况及表观弥散系数(apparent diffusion coefficient,ADC)评价放化疗疗效,并与生存相结合进行预后分析。结果 (1)CT评价的CR、PR和NR三组无进展生存率差异有统计学意义(χ~2=10.906,P=0.001),三组原发灶放疗前ADC值依次逐渐升高,ADC值变化幅度逐渐减小,放疗末ADC值PR组明显高于NR组。(2)放疗末原发灶及淋巴结DWI高信号完全消失组生存情况明显优于部分消失组(χ~2=7.521,P=0.006),高信号完全消失组放疗前原发灶ADC值较低,放疗末原发灶及残余淋巴结ADC值升高更显著。(3)CT疗效评价为PR的34例的患者中,放疗末有7例原发灶及淋巴结DWI高信号完全消失,无局部复发者;另27例原发灶及淋巴结DWI高信号未完全消失者,共有20例出现局部复发(0vs 77.0%)。(4)CT结合DWI综合疗效评价,完全缓解组与部分缓解组1、2、3、4年无进展生存率分别为66.7%、33.3%、25.0%、25.0%和44.0%、4.0%、4.0%、4.0%,无缓解组生存期最长者10个月,χ~2=13.896,P<0.001。Cox回归模型多因素分析结果显示非手术N分期、CT结合DWI疗效评价为独立预后影响因素。结论 DWI能对肺癌放化疗疗效进行判断并预测预后。DWI检查可弥补CT在评价瘤细胞功能状态改变方面疗效的不足,二者相结合共同评价疗效可能更客观,更能提示预后。

OBJECTIVE At present,the therapeutic effect of lung cancer is mainly judged by observing the changes of tumor volume,but there are some limitations in that of tumor cell function.The purpose of this study was to investigate the application value of CT combined with DWI in the evaluation of therapeutic effect of non-small cell lung cancer.METHODS From 2010-09-01 to 2014-09-30,forty-eight patients with lung cancer received with 3-dimensional conformal radiotherapy,with the median dose of 60Gy（50-66Gy）given at conventional fractions.CT and DWI were conducted before and at the end of radiotherapy.Therapeutic effect was evaluated by CT,the status of hyperintense expression in DWI and ADC value.The prognosis analysis was performed associated with the above factors.RESULTS The survival rates of the CR,PR and NR group had significant difference（χ~2=10.906,P=0.001）.The pre-radiotherapy ADC value of the primary tumor in CR,PR and NR group were gradually increased and the ADC value decreased gradually.The post-radiotherapy ADC value of PR group was significantly higher than that of NR group.The survival rates of patients with hyperintense both primary lung tumor and metastatic lymph node disappeared at the end of radiotherapy were significantly better than those not completely disappeared group（χ~2=7.521,P=0.006）.Compared with the hyperintense not disappared group,the pre-radiotherapy ADC value of the primary tumor was lower,the post-radiotherapy ADC value was higher and the value of ADC was increased more significantly in the hyperintense disappared group.There was no significant difference in the pre-radiotherapy ADC value of metastatic lymph node between the two groups.But compared with the hyperintense not disappared group,the post-radiotherapy ADC value was higher and the ADC value of the metastatic lymph node was increased more significantly in the hyperintense disappared group.Therapeutic effect was re-evaluated by CT combined with the status of hyperintense expression in DWI.The 1-,2-,3-,4-year survival rates of the CR and PR group were 66.7%,33.3%,25.0%,25.0% and 44.0%,4.0%,4.0%,4.0%,respectively.The longest survival period of the patients in NR group was ten months.The multivariate analysis of Cox regression model indicated that the therapeutic effect evaluated by CT combined with the status of hyperintense expression in DWI and non-surgical N staging were independently influence factors of prognosis.CONCLUSIONS Examination of DWI can be used to evaluate the therapeutic effect and predict prognosis of lung cancer treated with 3D-CRT or IMRT.DWI examination can make up for the lack of CT in evaluating therapeutic effect of non-small cell lung cancer.We strongly recommend that using CT combined with DWI to evaluate the therapeutic effect after radiotherapy of lung cance is more accurately.