本底选择对^99mTc-MIBI显像预测鼻咽癌多重耐药的影响

Influence of different backgrounds of ^(99m)Tc-MIBI SPECT on predicting the efficacy of neoadjuvant chemotherapy for nasopharyngeal carcinoma

目的:选择合理的判断指标和可行的图像分析方法,评价^(99m)Tc-MIBI核素显像预测鼻咽癌多重耐药的可能性。方法:选取32例病理证实为局部晚期鼻咽癌的患者,治疗前行^(99m)Tc-MIBI核素显像,在病灶最明显的横断面图像上获取病灶的放射性计数,以脑部、斜方肌、肺部作为本底分别计算早期、延迟显像的肿瘤摄取比值和清除率,以MRI结果作为疗效评价标准,绘制受试者工作特征(receiver operating characteristic,ROC)曲线选择合适的图像分析方法。结果:高反应组的早期和延迟期摄取比值均大于低反应组,差异有统计学意义,而高反应组与低反应组之间清除率差异无统计学意义。ROC曲线分析显示,早期和延迟摄取比值诊断化疗耐药性,均以脑部为本底时效果最佳;曲线下面积分别为0.943(SE=0.042;95%CI:0.860~1.026;P=0.002)和0.929(SE=0.050;95%CI:0.831~1.027;P=0.02),最佳诊断值分别为23.29和19.14;前者灵敏度为91.4%,特异度为80.0%,后者灵敏度为85.7%,特异度为77.3%。结论:以脑部为本底计算^(99m)TcMIBI摄取比值是诊断鼻咽癌新辅助化疗耐药性的理想指标。

Objective：To investigate the influence of different backgrounds of double-phase technetium-^99m methoxyisobutylisonitrile （^99mTc-MIBI） SPECT on predicting the efficacy of neoadjuvant chemotherapy for nasopharyngeal carcinoma.Methods：Thirty-two patients of nasopharyngeal carcinoma proven by pathology were chosen. All patients adopted double-phase^99mTc-MIBI SPECT before chemotherapy. The regions of interest （ROIs） drawn in the transverse slices with obvious lesions were copied to cerebrum, trapezius and lung. The relationships between efifcacy of neoadjuvant chemotherapy and the early uptake ratio, late uptake ratio and washout rate of^99mTc-MIBI were evaluated. The receiver operating characteristic （ROC） curve was made according to MRI results to determine the cutoff value of diagnosis.Results：The high response group had higher early uptake ratio and late uptake ratio than the low response group. The early uptake ratio of^99mTc-MIBI was best when cerebrum was set as background. The area under ROC curve （ROC-AUC） was 0.943 （SE=0.042; 95%CI=0.860-1.026;P=0.002）. The sensitivity and speciifcity were 91.4% and 80.0%, respectively. The late uptake ratio of99mTc-MIBI was best when cerebrum was set as background, with AUC of 0.929 （SE=0.050; 95%CI=0.831-1.027;P=0.02）, sensitivity of 85.7%, and speciifcity of 77.3%.Conclusion：When cerebrum is chosen as background, the uptake ratio of^99mTc-MIBI on predicting the efifcacy of chemotherapy for nasopharyngeal carcinoma is a perfect index.