Dong Xu, Chunrong Yu, Hongjun Hou, Xuexi Zhang
WeiHai Central Hospital, Weihai City, ShanDong, China.
GE Healthcare, Shanghai, China.
BJR Open. 2019 May 14;1(1):20180023. doi: 10.1259/bjro.20180023. eCollection 2019.
Lymph node metastasis is an important trait of breast cancer, and tumors with different lymph node statuses require various clinical treatments. This study was designed to evaluate the lymph node metastasis of breast cancer through pharmacokinetic and histogram analysis via dynamic contrast-enhanced (DCE) MRI.
A retrospective analysis was conducted to quantitatively evaluate the lymph node statuses of patients with breast cancer. A total of 75 patients, i.e. 34 patients with lymph node metastasis and 41 patients without lymph node metastasis, were involved in this research. Of the patients with lymph node metastases, 19 had sentinel lymph node metastasis, and 15 had axillary lymph node metastasis. MRI was conducted using a 3.0 T imaging device. Segmentation was carried out on the regions of interest (ROIs) in breast tumors under DCE-MRI, and pharmacokinetic and histogram parameters were calculated from the same ROIs. Mann-Whitney test was performed, and receiver operating characteristic curves for the parameters of the two groups were constructed to determine their diagnostic values.
Pharmacokinetic parameters, including Ktrans, Kep, area under the curve of time-concentration, and time to peak, which were derived from the extended Tofts linear model for DCE-MRI, could highlight the tumor areas in the breast and reveal the increased perfusion. Conversely, the pharmacokinetic parameters showed no significant difference between the patients with and without lymph node metastases. By contrast, the parameters from the histogram analysis yielded promising results. The entropy of the ROIs exhibited the best diagnostic ability between patients with and without lymph node metastases ( < 0.01, area under the curve of receiver operating characteristic = 0.765, specificity = 0.706, sensitivity = 0.780).
In comparison with the pharmacokinetic parameters, the histogram analysis of the MR images could reveal the differences between patients with and without lymph node metastases. The entropy from the histogram indicated that the diagnostic ability was highly sensitive and specific.
This research gave out a promising result on the differentiating lymph node metastases through histogram analysis on tumors in DCE-MR images. Histogram could reveal the tumors heterogenicity between patients with different lymph node status.
淋巴结转移是乳腺癌的一个重要特征，不同淋巴结状态的肿瘤需要不同的临床治疗方法。本研究旨在通过动态对比增强（DCE）MRI的药代动力学和直方图分析来评估乳腺癌的淋巴结转移情况。
进行回顾性分析以定量评估乳腺癌患者的淋巴结状态。本研究共纳入75例患者，其中34例有淋巴结转移，41例无淋巴结转移。在有淋巴结转移的患者中，19例有前哨淋巴结转移，15例有腋窝淋巴结转移。使用3.0T成像设备进行MRI检查。在DCE-MRI下对乳腺肿瘤的感兴趣区域（ROIs）进行分割，并从相同的ROIs计算药代动力学和直方图参数。进行Mann-Whitney检验，并构建两组参数的受试者操作特征曲线以确定其诊断价值。
从DCE-MRI的扩展Tofts线性模型得出的药代动力学参数，包括转运常数（Ktrans）、速率常数（Kep）、时间-浓度曲线下面积和达峰时间，能够突出乳腺中的肿瘤区域并显示灌注增加。相反，有和无淋巴结转移患者之间的药代动力学参数无显著差异。相比之下，直方图分析的参数产生了有前景的结果。ROIs的熵在有和无淋巴结转移患者之间表现出最佳诊断能力（<0.01，受试者操作特征曲线下面积=0.765，特异性=0.706，敏感性=0.780）。
与药代动力学参数相比，MR图像的直方图分析能够揭示有和无淋巴结转移患者之间的差异。直方图的熵表明诊断能力具有高度敏感性和特异性。
本研究通过对DCE-MR图像中的肿瘤进行直方图分析，在鉴别淋巴结转移方面给出了有前景的结果。直方图能够揭示不同淋巴结状态患者之间肿瘤的异质性。
