动态对比增强MRI定量参数与乳腺癌预后因子的相关性研究

Correlation of quantitative parameters on dynamic contrast-enhanced MRI with prognostic factors

目的：探讨动态对比增强MRI（DCE-MRI）与乳腺癌预后因子（包括强化形态、肿块大小及病理分级）的相关性。方法回顾性分析经手术证实为乳腺癌、术后经免疫组织化学检测获得病理分级和核分级，且术前行乳腺DCE-MRI检查的113例患者（120个病灶）的临床和影像资料。患者行乳腺DCE-MRI检查获得定量参数，包括容量转移常数（Ktrans）、速率常数（kep）和血管外细胞外间隙容积比（ve）。对103个浸润性导管癌病灶进行病理分级及核分级，再据此将病灶分为病理分级Ⅰ、Ⅱ级组（低级别组）与病理分级Ⅲ级（高级别组），核分级Ⅰ、Ⅱ级组（低级别组）与核分级Ⅲ级（高级别组）。根据乳腺癌不同强化形态分为肿块型强化组与非肿块型强化组；根据肿块最大径，将病灶大小分为≤20 mm组及〉20 mm组。采用Mann-Whitney U检验比较不同肿块强化形态、大小、病理分级乳腺癌组间的DCE-MRI定量参数，采用Spearman法评价DCE-MRI定量参数和肿块大小的相关性。结果肿块型乳腺癌（92个病灶）的Ktrans值高于非肿块型乳腺癌（28个病灶），差异有统计学意义（P〈0.05）；肿块型与非肿块型组间的kep、ve值差异均无统计学意义（P〉0.05）。最大径≤20 mm组（40例）和〉20 mm组（52例）间的Ktrans、kep、ve值差异均无统计学意义（P〉0.05）。肿块型乳腺癌的平均最大径为（2.38±0.95）cm，肿块大小与定量参数Ktrans无明显相关性（r=0.238，P=0.038），与kep、ve无相关性（r值分别为0.223、0.070，P值分别为0.052、0.547）。高级别病理分级（22个）及核分级组（15个）的Ktrans、kep值均高于低级别组（52个、56个），差异有统计学意义（P〈0.05）；高、低级别病理分级及核分级组的ve值差异均无统计学意义（P〉0.05）。结论 DCE-MRI定量参数与乳腺癌预后因子有关，高Ktrans、kep值及低ve值提示预后较差。

Objective To investigate the correlation between parameters obtained from dynamic contrast-enhanced magnetic resonance imaging （DCE-MRI） and prognostic factors （including enhanced morphology, tumor size, histological grade, nuclear grade） of breast carcinoma. Methods One hundred and thirteen breast cancer cases with 120 lesions confirmed histopathologically were retrospectively analyzed. All the patients underwent the DCE-MRI before the surgery, and the immunohistochemistry after the operation was performed to get the histological and nuclear grade. The volume transfer constant（Ktrans）, rate constant （kep）, and volume of extravascular extracellular space per unit volume of tissue（ve） were calculated through the DCE-MRI postprocessing. One hundred and three invasive ductal carcinomas were examined with the immunohistochemistry to get results of the histological and nuclear grade. Accordingly, the 103 lesions were divided in two subgroups： the tumors of histological grade Ⅰ,Ⅱ （low histological grade） and tumors of grade III （high histological grade）;tumors of nuclear gradeⅠ,Ⅱ（low nuclear grade） and tumors of grade Ⅲ （high nuclear grade）. All the tumors were divided into mass-like type and non mass-like type according the enhanced morphology, as well as size ≤20 mm type and size 〉20 mm type respectively. Correlations between parameters and enhanced morphology, tumor size, histological grade, nuclear grade were analyzed through Mann-Whitney U test,the correlation between the tumor size and quantitative parameters was tested with Spearman correlation. Results Mean Ktrans was higher in tumors with mass-like＆nbsp;tumors （n=92） than with non mass-like tumors（n=28）, and the differences was statistically significant （P〈0.05）. There was no significant differences between mass-like tumors and non mass-like tumors in both mean kep and ve （P〉0.05）. There was no significant differences between tumor size≤20 mm（n=40） and size〉20 mm （n=52） in mean Ktrans ,kep and ve respectively （P〉0.05） .The mean maximal size of mass-like tumors was （2.38± 0.95） cm, and there was no significant correlations between the tumors size and Ktrans （r=0.238,P=0.038）, kep and ve （r values were 0.223 and 0.070, respectively, P values were 0.052 and 0.547 respectively） . Mean Ktrans, kep was higher in tumors with a high histological grade （n=22） than with a low histological grade（n=52）, also was higher in tumors with a high nuclear grade（n=15） than with a low nuclear grade （n=56）, with statistically significant differences （P〈0.05）. There was no significant differences between tumors with high and low histological grade, or tumors with high and low nuclear grade in mean ve （P〉0.05）. Conclusion There is correlation between parameters obtained from DCE-MRI and prognostic factors of breast cancers, with higher Ktrans and kep, or lower ve, indicating poor prognostic factors.