目的：研究双能CT对肿瘤总碘含量的量化测定在非小细胞肺癌（non-small cell lung cancer, NSCLC）非手术治疗后疗效评估中的应用价值,并探究建立基于肿瘤碘含量测定的疗效评价标准的可行性。方法：选取30例经活检证实且临床资料完整的晚期NSCLC病例,在非手术治疗的第一疗程前、后行双能CT扫描,经图像后处理软件测得30枚靶病灶的最大径、CT值及总碘含量。根据实体瘤疗效评价标准（response evaluation criteria in solid tumors,RECIST）、Choi标准及双能CT标准分别对30枚靶病灶进行评估,采用配对t检验分别比较病灶最大径、CT值及碘含量在治疗前后的差异,Kappa检验分别比较双能CT检查结果与RECIST、Choi标准评估结果间的一致性,并采用配对χ2检验分别比较双能CT标准评估的部分缓解率与RECIST标准、Choi标准评估结果间的差异。结果：靶病灶的最大径在治疗前后的变化较小,平均变化率仅为缩小[(-3.45±15.76）%（P>0.05）];CT值的变化率亦不明显,平均变化率为减低[（-4.80±25.00）%（P>0.05）]。靶病灶总碘含量的平均变化率为减低[（-10.47±23.34）%（P<0.05）],较最大径及CT值显著,且差异有统计学意义,与RECIST评估结果相比的一致性（Kappa=0.302, P<0.05）,双能CT标准与Choi标准评估结果间的一致性更好（Kappa=0.718, P<0.05）;双能CT评估的部分缓解率显著高于RECIST标准（P<0.05）,而与Choi标准相比无明显差异（P>0.05）。结论：双能CT测定的病灶碘含量较最大径、CT值在治疗前后变化更显著,且差异有统计学意义,表明碘含量能更早地反映NSCLC肿瘤对药物的应答。相较于RECIST,采用总碘含量结合最大径测量建立的双能CT标准的评估结果与兼顾肿瘤血供的Choi标准间的一致性更好,因此双能CT标准评估化疗疗效的建立具有可行性。
Objective: To investigate the level of iodine-uptake estimated by dual-energy CT (DECT) for assessing the therapy response of non-small cell lung cancer (NSCLC) treated with chemotherapy or target therapy and to determine whether DECT criteria can evaluate the response of NSCLC treated with chemotherapy or target therapy. Methods: Thirty NSCLC patients receiving chemotherapy or target therapy and contrast-enhanced DECT scan at baseline and follow-up (at least 8 weeks and one time point) were analyzed retrospectively. Iodine-uptake level of the target lesion was measured and compared with the longest diameter and CT value of the target lesion. The 30 target lesions were evaluated by RECIST criteria, Choi criteria and dual energy CT criteria, respectively. Paired t test was used to compare the longest diameter, CT value and iodine-uptake level of the lesion at baseline and follow-up examination. Kappa statistics were used to evaluate the agreement between the results of the three response evaluation items. McNemar test was used to compare the partial response rate of DECT criteria, RECIST criteria and Choi criteria. Results: The lowering of iodine-uptake level assessed by DECT between baseline and follow-up was distinct (-10.47±23.34)%, P<0.05), while the longest diameter and CT density did not show significant change[ (-3.45±15.76)%, P>0.05; （-4.80±25.00）%, P>0.05]. DECT had better consistency with Choi criteria(kappa=0.718, P<0.05) than with RECIST （kappa=0.302, P<0.05). The partial response rate of DECT criteria had significant difference with RECIST criteria (P<0.05) and no significant difference with Choi criteria (P>0.05). Conclusions: The iodine-uptake level measured by DECT is more sensitive to evaluate the early response of NSCLC when treated with chemotherapy and target therapy than both the longest diameter and CT value. DECT criteria based on iodine uptake level and longest diameter has the potential to be a feasible method to evaluate the response of NSCLC treated with chemotherapy and target therapy.
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