定量DCE-MRI在局部进展期直肠癌疗效评估中的应用

Quantitative DCE-MRI to evaluate the neoadjuvant radioc hemotherapy effect in patients with locally advanced rectal cancer

目的:评价定量动态增强磁共振成像(dynamic contrast enhanced-MRI,DCE-MRI)在局部进展期直肠癌患者新辅助治疗疗效评估中的应用价值。方法:收集我院34例局部进展期直肠癌患者,于新辅助治疗前、后分别行DCE-MRI检查,根据肿瘤退缩分级,将其分为有反应组(mr TRG1、mr TRG2和mr TRG3)和无反应组(mr TRG4和mr TRG5)。测量并比较治疗前后总体及两组间DCE-MRI定量参数K^(trans)(容量转移常数)、Kep(速率常数)以及Ve(血管外细胞外间隙容积分数)的差异。结果:34例患者,治疗后K^(trans)[治疗前、后分别为(1. 48±0. 80)/min,(0. 88±0. 45)/min,P <0. 001]、Kep[治疗前为(3. 29±1. 25)/min,治疗后为(2. 12±1. 18)/min,P <0. 001]均较治疗前减低,有反应组、无反应组的K^(trans)、Ve值在治疗前和治疗后的变化差值均有统计学意义,其中,治疗前有反应组的K^(trans)值为(1. 93±0. 81)/min、Ve值为0. 59±0. 27、治疗后变化差值相应为(-1. 11±66)/min、-0. 14±0. 16,无反应组的K^(trans)值为(0. 82±0. 49)/min、Ve值为0. 35±0. 16,相应的变化差值为(-0. 03±19)/min、0. 21±0. 27。结论:定量动态增强磁共振成像对局部进展期直肠癌新辅助治疗疗效评价具有一定的价值。

Objective: To prospectively investigate the changes of quantitative parameters in dynamic contrast enhanced-MRI (DCE-MRI) in locally advanced rectal cancer patients before and after the neoadjuvant radiochemotherapy. Methods: Thirty-four patients with locally advanced rectal cancer (in stage T 3,T 4) under-went DCE-MRI before and 1 week after neoadjuvant radiochemotherapy.The patients were classified into a reaction group (CR include mrTRG1、mrTRG2 and mrTRG3) or a non-CR(include mrTRG4 and mrTRG5) group according to the (TRG).The following DCE-MRI quantitative parameters values (K^trans ,Kep ,Ve) were measured and compared between the CR and non-CR groups before and after treatment. Results: There were 18 and 16 patients in CR and non-CR groups.The K trans [(1.48±0.80)/min,(0.88±0.45)/min, P <0.05] and K ep [(3.29±1.25)/min,(2.12±1.18)/min, P <0.05] were lower than those in prior-treatment in total patients.Before neoadjuvant radiochemotherapy,the K^trans and V e were higher in CR group[(1.93±0.81)/min,0.59±0.27] than those in non-CR group [(0.82±0.49)/min,0.35±0.16],and these differences were statistically significant.After neoadjuvant radiochemotherapy,the changed value of K^trans [(-1.11±66)/min] and changed value of Ve (0.21±0.27) between the two groups were just reversed. Conclusion: Quantitative parameters of DCE-MRI provided a new noninvasive way to reflect the changes of hemodynamics in locally advanced rectal cancer patients with neoadjuvant radiochemotherapy.