ADC和nADC值对局部进展期直肠癌新辅助放化疗疗效评估价值

Value of ADC and nADC in evaluating the efficacy of neoadjuvant radiotherapy and chemotherapy for locally advanced rectal cancer

目的探讨瘤体表观扩散系数(ADC)值和标准化ADC(nADC)值评价局部进展期直肠癌(LARC)新辅助放化疗(NCRT)疗效的价值。方法回顾性分析广西医科大学附属肿瘤医院2016-12-26-2020-04-03收治的NCRT后行根治性手术的56例LARC患者,基线、NCRT后6〜8周常规行盆腔MRI及扩散加权成像(DWI)检查。根据术后病理肿瘤退缩分级(TRG)标准,将患者分为退缩良好组及退缩不良组,分别在瘤体(T)最大层面、无肿瘤直肠壁(R)、膀胱尿液(U)及臀大肌(GMM)处测量3次ADC值,取平均值,分别计算nADC(肿瘤ADC值/参照物ADC值)、△ADC值和△nADC值。采用t和U检验比较各值在退缩良好组及退缩不良组间的差异。分别绘制ADC值、nADC值、△ADC值及△nADC值受试者工作特性曲线(ROC),评估其诊断效能。结果56例LARC患者中退缩不良组41例,退缩良好组15例。2组患者NCRT后ADC_(T)(z=6.509,P<0.001)及nADC值(nADC_(T/R)):t=11.527,P<0.001;nADC_(T/U):z=6.649,P<0.001;nADC_(T/GMM):z=6.053,P<0.001)均高于NCRT前,差异有统计学意义。NCRT后,退缩良好组ADC_(T/R)为(1.535±0.207)×10^(-3)mm^(2)/s,高于退缩不良组的(1.258±0.230)×10^(-3)mm^(2)/s,t=0.204,P<0.001;nADC_(T/R)为1.058±0.147,高于退缩不良组的0.863±0.171,t=3.896,P<0.001;nADC_(T/U)为0.467±0.067,高于退缩不良组的0.362±0.105,z=-3.266,P=0.001;nADC_(T/GMM)为0.984±0.131,高于退缩不良组的0.786±0.192,z=-3.654,P=0.001。NCRT后退缩良好组△ADC_(T)(z=2.263,P<0.001)、△nADC_(T/K)(z=1.719,P=0.005)、△nADC_(T)(z=2.123,P<0.001)和△nADC_(T/UMM)(z=1.940,P=0.001)上升幅度均大于退缩不良组。ROC分析结果显示,△ADG_(T)值诊断效能较好,曲线下面积为0.841(95%CI:0.740〜0.942),阈值为0.356×10^(-3)mm^(2)/s,敏感度为100%,特异度为68.3%。结论在评价LARC患者NCRT后疗效上,治疗前ADC及各nADC值均无预测价值,而治疗后ADC及nADC值有较好的诊断效能,但未能证实nADC值的诊断效能优于ADC值。

Objective To explore the value of tumor apparent diffusion coefficient(ADC)value and standardized ADC(nADC)value in evaluating the efficacy of neoadjuvant radiotherapy(NCRT)in locally advanced rectal cancer(LARC).Methods Retrospective analysis of 56 LARC patients admitted to the Cancer Hospital of Guangxi Medical University 2016-12-26-2020-04-03 who underwent radical surgery after NCRT cycle.Routine pelvic MRI and diffusion weighting were performed at baseline and 6~8 weeks after NCRT Imaging(DWI)inspection.According to the postoperative pathological tumor regression classification(TRG)criteria,the patients were divided into good regression and poor regression groups,respectively at the largest level of tumor(T),rectal disease-free bowel wall(R),bladder and urine Measure the ADC values at the fluid(U)and gluteus maximus(GMM)3 times,take the average value,and calculate the nADC(tumor ADC value/reference ADC value).△ADC value and△nADC value respectively.The t and U test were used to compare the differences between the good regression and poor regression group.Drawed ADC value,nADC value,△ADC value and△nADC value receiver operating characteristic curve(ROC)respectively to evaluate its diagnostic efficacy.Results Among the 56 LARC patients,41 were in the poor regression group and 15 were in the good regression group.The ADC value and nADC value of the two groups of patients after NCRT were higher than before NCRT,and the difference was statistically significant(ADC_(T):z=6.509,P<0.001;nADC_(T/R):t=11.527,P<0.001;nADC_(T):z=6.649,P<0.001;nADC_(T/GMM):z=6.053,P<0.001).After NCRT,the ADC_(T)(z=6.509,P<0.001)and nADC value(nADC_(T/R):t=11.527,P<0.001;nADC_(T/U):z=6.649,P<0.001,nADC_(T/GMM):z=6.053,P<0.001)were all higher than before NCRT in two groups,and the difference was statistically significant.The ADC_(T) of the good regression group was(1.535±0.207)×10^(-3) mm^(2)/s,which was higher than that of the poor regression group[(1.258±0.230)×10^(-3) mm^(2)/s],t=0.204,P<0.001.The nADC_(T/R)was 1.058±0.147,which was higher than the poor regression group(0.863±0.171),t=3.890,P<0.001.The nADC_(T/U)was 0.467±0.067,which was higher than the poor regression group(0.362±0.105),z=-3.266,P=0.001.The ADC_(T/GMM) was 0.984±0.131,which was higher than the poor regression group(0.786±0.192),3.654,P=0.001.After NCRT,the△ADC value and△nADC value of the good regression group increased more than the poor regression group(△ADC_(T):z=2.263,P<0.001;△nADC_(T/R):z=1.719,P=0.005;△nADC_(T/U):z=2.123,P<0.001;△nADC_(T/GMM):z=1.940,P=0.001).ROC analysis results showed that the diagnostic efficiency of△ADC_(T)value was better,the area under the curve was 0.841(95%CI:0.740-0.942),the threshold was 0.356×10^(-3)mm^(2)/s,the sensitivity was 100%,and the specificity was 68.3%.Conclusion In evaluating the efficacy of LARC patients after NCRT,the ADC and nADC values before treatment have no predictive value,and the ADC and nADC values after treatment have better diagnostic performance,but it has not been confirmed that the diagnostic performance of the nADC value is better than the ADC value.