Contrast-enhanced ultrasonography assessment of gastric cancer response to neoadjuvant chemotherapy
Contrast-enhanced ultrasonography assessment of gastric cancer response to neoadjuvant chemotherapy
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超声造影评估胃癌新辅助化疗的反应
DOI：
10.3748/wjg.v18.i47.7026
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发表时间：
2012-12-21
影响因子：
4.3
通讯作者：
Chen, Li
中科院分区：
文献类型：
--
作者：
Ang, Jian;Hu, Liang;Chen, Li
目的：为定量评估双对比超声（DCUS）检测肿瘤对术前化疗早期反应的能力，对2011年9月至2012年2月间43例接受新辅助化疗后行根治性切除术的胃癌患者进行分析。术前化疗方案为氟尿嘧啶+奥沙利铂或S-1 +奥沙利铂，2-4个周期，6-12周。所有患者在术前化疗两个疗程前后均行对比增强CT扫描和DCUS检查。采用实体瘤疗效评价标准（RECIST 1.1）通过CT评估治疗疗效。通过DCUS评估肿瘤面积，因为与正常胃壁相比，在造影期间肿瘤血管分布导致胃癌的增强外观。根据Mandard肿瘤消退分级标准进行组织学分析，并用作参考标准。受试者操作特征（ROC）分析被用来评估DCUS参数的疗效，在区分组织病理学反应者从nonresponders.RESULTS：研究人群包括32名男性和11名女性，平均年龄为59.7 +/- 11.4岁。年龄、性别、组织学类型、肿瘤部位、T分期和N分期均与病理反应无关。应答者的平均肿瘤大小显著小于无应答者（15.7 +/- 7.4 cm vs 33.3 +/- 14.1 cm，P < 0.01）。根据Mandard的标准，27名患者被归类为缓解者，其中11名（40.7%）DCUS显示肿瘤尺寸缩小。而DCUS显示16例无应答者中仅有3例（18.8%）肿瘤缩小（P < 0.01）。ROC曲线下面积为0.64，95%CI为0.46-0.81。在ROC曲线分析中计算几个截断点对诊断参数的影响。通过最大化Youden指数（灵敏度+特异性-1），确定了区分应答者和非应答者的最佳截止点，其最佳灵敏度为62.9%，特异性为56.3%。使用该截止点，DCUS区分应答者和非应答者的阳性和阴性预测值分别为70.8%和47.4%。DCUS评估疗效的总体准确性为60.5%，略高于CT评估疗效的53.5%（P = 0.663）。尽管优势在统计学上不显著，但可能是由于评估的病例数量较少。DCUS能够识别CT成像未显示形态学变化的反应者的灌注减少，这可能会被纤维化和水肿等治疗效果所堵塞。结论：DCUS可能代表一种创新工具，可以更准确地预测局部晚期胃癌患者手术切除前新辅助化疗的组织病理学反应。(C)2012年百世登。All rights reserved.
AIM: To quantitatively assess the ability of double contrast-enhanced ultrasound (DCUS) to detect tumor early response to pre-operative chemotherapy.METHODS: Forty-three patients with gastric cancer treated with neoadjuvant chemotherapy followed by curative resection between September 2011 and February 2012 were analyzed. Pre-operative chemotherapy regimens of fluorouracil + oxaliplatin or S-1 + oxaliplatin were administered in 2-4 cycles over 6-12 wk periods. All patients underwent contrast-enhanced computed tomography (CT) scan and DCUS before and after two courses of pre-operative chemotherapy. The therapeutic response was assessed by CT using the response evaluation criteria in solid tumors (RECIST 1.1) criteria. Tumor area was assessed by DCUS as enhanced appearance of gastric carcinoma due to tumor vascularity during the contrast phase as compared to the normal gastric wall. Histopathologic analysis was carried out according to the Mandard tumor regression grade criteria and used as the reference standard. Receiver operating characteristic (ROC) analysis was used to evaluate the efficacy of DCUS parameters in differentiating histopathological responders from non-responders.RESULTS: The study population consisted of 32 men and 11 women, with mean age of 59.7 +/- 11.4 years. Neither age, sex, histologic type, tumor site, T stage, nor N stage was associated with pathological response. The responders had significantly smaller mean tumor size than the non-responders (15.7 +/- 7.4 cm vs 33.3 +/- 14.1 cm, P < 0.01). According to Mandard's criteria, 27 patients were classified as responders, with 11 (40.7%) showing decreased tumor size by DCUS. In contrast, only three (18.8%) of the 16 non-responders showed decreased tumor size by DCUS (P < 0.01). The area under the ROC curve was 0.64, with a 95% CI of 0.46-0.81. The effects of several cut-off points on diagnostic parameters were calculated in the ROC curve analysis. By maximizing Youden's index (sensitivity + specificity - 1), the best cut-off point for distinguishing responders from non-responders was determined, which had optimal sensitivity of 62.9% and specificity of 56.3%. Using this cut-off point, the positive and negative predictive values of DCUS for distinguishing responders from non-responders were 70.8% and 47.4%, respectively. The overall accuracy of DCUS for therapeutic response assessment was 60.5%, slightly higher than the 53.5% for CT response assessment with RECIST criteria (P = 0.663). Although the advantage was not statistically significant, likely due to the small number of cases assessed. DCUS was able to identify decreased perfusion in responders who showed no morphological change by CT imaging, which can be occluded by such treatment effects as fibrosis and edema.CONCLUSION: DCUS may represent an innovative tool for more accurately predicting histopathological response to neoadjuvant chemotherapy before surgical resection in patients with locally-advanced gastric cancer. (C) 2012 Baishideng. All rights reserved.