[扩散加权磁共振成像在食管癌放疗患者中的预测价值：一项动物试验]

[Predictive value of diffusion-weighted magnetic resonance imaging in patients with esophageal carcinoma treated with radiotherapy: an animal trial].

作者信息

Zhang A D, Wang Y F, Shi G F, Han C, Zhang J, Wang L, Liu H, Li Y

机构信息

Department of Radiotherapy, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.

Department of CT and MRI, the Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, China.

出版信息

Zhonghua Zhong Liu Za Zhi. 2019 Feb 23;41(2):102-106. doi: 10.3760/cma.j.issn.0253-3766.2019.02.005.

DOI:10.3760/cma.j.issn.0253-3766.2019.02.005

PMID:30862138

Abstract

To explore the value of diffusion-weighted magnetic resonance imaging (MR-DWI) technique in predicting the efficacy of radiotherapy in patients with esophageal cancer, using experimental animal models. BALB/c nude mice were subcutaneously injected with Eca-109 cell lines and then tumor formed. The experimental group (16 cases) received a single dose of 15 Gy (6 MV X-rays) delivered by a medical linear accelerator, while the control group (24 cases) did not receive any treatment. The two groups were scanned every other day, started one day before the radiotherapy. The scanning sequences included T1-weight imaging, T2-weight imaging, and DWI. The observation time was 1 month. According to the changes of the tumor volume and apparent diffusion coefficient (ADC) value of the two groups, 7 key time points were selected to observe the difference of cell density and tissue necrosis ratio between the two groups (6 cases in each group). From day 7 after radiotherapy, the experimental group had statistically smaller volume of transplanted tumors than the control group, namely (1.729±0.906) cm(3) vs (2.671±0.915) cm(3)(<0.05). From day 3 after radiotherapy, the experimental group had statistically higher ADC values [(1.017±0.255)×10(-6) vs (0.833±0.142)×10(-6) mm(2)/s, <0.05], lower cell density of transplanted tumor (25.56±1.40 vs 33.48±4.18%, <0.05), and less proportion of tissue necrosis [(32.19±1.21) % vs (29.16±2.16)%, <0.05], respectively. The ADC value was negatively correlated with cell density (=-0.703, <0.001) and positively correlated with tissue necrosis ratio (=0.658, =0.003). Single dose of large fraction radiotherapy could inhibit the growth of xenograft. ADC values may change at the early stage prior to morphological changes of tumor. The change of cell density and necrosis ratio of transplanted tumor are in line with the change of ADC value. MR-DWI has the value of early prediction of esophageal cancer radiotherapy efficacy.

摘要

为探讨磁共振扩散加权成像（MR-DWI）技术在预测食管癌患者放疗疗效中的价值，采用实验动物模型。将Eca-109细胞系皮下注射到BALB/c裸鼠体内，待肿瘤形成。实验组（16只）接受医用直线加速器单次剂量15 Gy（6 MV X射线）照射，对照组（24只）不接受任何治疗。两组在放疗前1天开始每隔1天进行扫描。扫描序列包括T1加权成像、T2加权成像和DWI。观察时间为1个月。根据两组肿瘤体积和表观扩散系数（ADC）值的变化，选取7个关键时间点观察两组细胞密度和组织坏死率的差异（每组6只）。放疗后第7天起，实验组移植瘤体积较对照组明显减小，即（1.729±0.906）cm³ 对比（2.671±0.915）cm³（P<0.05）。放疗后第3天起，实验组ADC值较高[（1.017±0.255）×10⁻⁶对比（0.833±0.142）×10⁻⁶mm²/s，P<0.05]，移植瘤细胞密度较低（25.56±1.40对比33.48±4.18%，P<0.05），组织坏死比例较小[（32.19±1.21）%对比（29.16±2.16）%，P<0.05]。ADC值与细胞密度呈负相关（r=-0.703，P<0.001），与组织坏死率呈正相关（r=0.658，P=0.003）。单次大分割放疗可抑制移植瘤生长。ADC值可能在肿瘤形态学改变之前的早期就发生变化。移植瘤细胞密度和坏死率的变化与ADC值的变化一致。MR-DWI对食管癌放疗疗效具有早期预测价值。