Department of Radiology, Affiliated Hospital of Jiangnan University, The Forth People's Hospital of Wuxi City, Wuxi, Jiangsu, China.
Department of Intervention, Affiliated Hospital of Jiangnan University, The Forth People's Hospital of Wuxi City, Wuxi, Jiangsu, China.
J Xray Sci Technol. 2017;25(6):981-991. doi: 10.3233/XST-17271.
To explore the value of low-dose CT perfusion imaging (LDCTPI) technology and its perfusion parameters in assessing response of neoadjuvant chemotherapy (NAC) in patients with advanced gastric cancer (AGC).
Thirty patients with AGC were studied prospectively by LDCTPI to measure two parameters including blood flow (BF) and blood volume (BV) of tumor area before and after chemotherapy, respectively. All of the patients received two courses of NAC and surgical resection of gastric tumor within one week after chemotherapy, and then obtained the result of postoperative pathology response for chemotherapy. The comparisons of BF and BV values of AGC before and after chemotherapy were analyzed by paired-samples t-test, respectively; and the correlations between BF as well as BV decrease rates after NAC and the pathology response grade were analyzed by Spearman statistical test. Thirty patients were divided into effective and ineffective groups according to different pathology response grade. Comparisons of BF as well as BV decrease rates between effective and ineffective groups were analyzed by independent-samples t-test, respectively. Receiver operating characteristic (ROC) curves were used to determine the cutoff values of BF and BV decrease rates as evaluation indicators of AGC after NAC and calculate area under the curve (AUC).
There were significant differences in BF and BV values of AGC between before and after NAC (p < 0.001), respectively, and there were obvious correlations between BF as well as BV decrease rates and pathology response grade (r = 0.660, p < 0.001; r = 0.706, p < 0.001), respectively. There were also significant differences in BF and BV decrease rates of AGC between effective and ineffective groups (P = 0.001), respectively. If BF decrease rate of 12.1% (AUC was 0.816, P = 0.005) was used as the cutoff value for chemotherapy effectiveness of AGC, the sensitivity of 82% and specificity of 84% were achieved, and if BV decrease rate of 32.8% (AUC was 0.844, P = 0.002) was used as the cutoff value for chemotherapy effectiveness of AGC, the sensitivity of 82% and specificity of 89% were achieved.
BF and BV decrease rates have potential to be used as effective indicators to assess chemotherapy efficacy of AGC from the hemodynamics.
探讨低剂量 CT 灌注成像（LDCTPI）技术及其灌注参数在评估晚期胃癌（AGC）新辅助化疗（NAC）反应中的价值。
前瞻性地对 30 例 AGC 患者进行 LDCTPI 测量，分别测量化疗前后肿瘤区域的血流（BF）和血容量（BV）两个参数。所有患者均接受两周期 NAC，并在化疗后一周内行胃肿瘤切除术，然后获得术后病理反应结果用于化疗。采用配对样本 t 检验分别分析 AGC 化疗前后 BF 和 BV 值的变化，采用 Spearman 统计检验分析 NAC 后 BF 和 BV 下降率与病理反应分级的相关性。根据不同的病理反应分级，将 30 例患者分为有效组和无效组。采用独立样本 t 检验分别分析有效组和无效组 BF 和 BV 下降率的差异。采用受试者工作特征（ROC）曲线确定 BF 和 BV 下降率作为 NAC 后 AGC 评价指标的截断值，并计算曲线下面积（AUC）。
NAC 前后 AGC 的 BF 和 BV 值差异均有统计学意义（P<0.001），BF 和 BV 下降率与病理反应分级均有明显相关性（r=0.660，P<0.001；r=0.706，P<0.001）。有效组和无效组 AGC 的 BF 和 BV 下降率差异均有统计学意义（P=0.001）。如果将 BF 下降率 12.1%（AUC 为 0.816，P=0.005）作为 AGC 化疗有效性的截断值，则灵敏度为 82%，特异性为 84%，如果将 BV 下降率 32.8%（AUC 为 0.844，P=0.002）作为 AGC 化疗有效性的截断值，则灵敏度为 82%，特异性为 89%。
BF 和 BV 下降率从血流动力学方面有潜力成为评估 AGC 化疗疗效的有效指标。
