目的

研究动态增强磁共振（DCE-MRI）评估中晚期低位直肠癌同步放化疗后疗效及预后的价值。

方法

选取2019年1月至2022年1月收治的112例中晚期低位直肠癌同步放化疗患者，根据实体瘤疗效评价标准分为稳定组（n=53例，病灶稳定）和进展组（n=59例，病灶进展）。均行DCE-MRI检查。对比两组同步放化疗前后DCE-MRI参数［容积转移产量（Ktrans）、速率常数（Kep）、血管外细胞外间隙容积分数（Ve）］。采用SPSS 22.0统计学软件处理数据，肿瘤形态指标、DCE-MRI参数采用（x± s）表示，组间对比采用独立样本t检验；复发率等计数资料计算其构成比，采用卡方检验；一致性分析采取kappa检验。 P＜0.05为差异有统计学意义。

结果

与同步放化疗前比较，放化疗后及放化疗结束1个月后直肠癌肿瘤长度、肿瘤肠壁厚度均明显降低（P＜0.05），但两组比较差异无统计学意义（P＞0.05）；两组同步放化疗前直肠癌肿瘤长度、肿瘤肠壁厚度比较差异无统计学意义（P＞0.05），稳定组放化疗后及放化疗1个月后直肠癌肿瘤长度、肿瘤肠壁厚度均低于进展组（P＜0.05）。稳定组同步放化疗前Ktrans、Kep高于进展组（P＜0.05），Ve较进展组比较差异无统计意义（P＞0.05）；两组同步放化疗后Ktrans、Kep、Ve均较同步放化疗前降低（P＜0.05）；稳定组同步放化疗后Ktrans、Kep低于进展组（P＜0.05），Ve较进展组比较差异无统计意义（P＞0.05）。随访1年，112例中晚期低位直肠癌患者中，失访6例，其中死亡6例；经病理学检查其余100例中晚期低位直肠癌患者中，复发16例，复发率为16%（16/100），DCE-MRI检查复发14例，复发率为14%（14/100），DCE-MRI与病理检查结果相比有较好一致性（Kappa=0.813，P=0.000）。

结论

DCE-MRI在中晚期低位直肠癌同步放化疗预后评估中有重要价值，值得推广。

Objective

To investigate the value of dynamic enhanced magnetic resonance imaging（DCE-MRI） in evaluating the efficacy and prognosis of middle and advanced low rectal cancer after concurrent chemoradiotherapy.

Methods

A total of 112 patients with concurrent chemoradiotherapy for middle and advanced low rectal cancer treated from January 2019 to January 2022 were selected and divided into stable group （n=53 cases， stable lesion） and progressive group （n=59 cases， progressive lesion） according to the evaluation criteria of solid tumor efficacy.All patients were examined by DCE-MRI.DCE-MRI parameters （volume transfer yield （Ktrans）， rate constant （Kep）， extracellular space volume fraction （Ve）） were compared between the two groups before and after simultaneous chemoradiotherapy.SPSS 22.0 was used to process the data.Tumor morphological indexes and DCE-MRI parameters were expressed as （x ± s）， and independent sample t test was used for comparison between groups.The composition ratio was calculated by counting data such as recurrence rate and Chi-Square test was used.Kappa test was used for consistency analysis.P＜0.05 was considered statistically significant.

Results

Compared with before chemoradiotherapy， the length of rectal cancer tumor and the thickness of tumor intestinal wall were significantly decreased after chemoradiotherapy and 1 month after chemoradiotherapy （P＜0.05）， but there was no statistical significance between the two groups （P＞0.05）.There was no significant difference in the length and thickness of rectal cancer before chemoradiotherapy between the two groups （P＞0.05）.The length and thickness of rectal cancer after chemoradiotherapy and 1 month after chemoradiotherapy in the stable group were lower than those in the advanced group （P＜0.05）.Before chemoradiotherapy， Ktrans and Kep in stable group were higher than those in advanced group（P＜0.05）， but there was no statistical difference in Ve group （P＞0.05）.Ktrans， Kep and Ve were decreased after chemoradiotherapy in both groups compared with before chemoradiotherapy （P＜0.05）.After concurrent chemoradiotherapy， Ktrans and Kep in stable group were lower than those in advanced group （P＜0.05）， and there was no statistical significance in Ve group compared with advanced group （P＞0.05）.1 year follow-up， 112 patients with middle and advanced low rectal cancer， 6 cases lost follow-up， including 6 cases died； Among the other 100 patients with middle and advanced low rectal cancer， 16 cases recurred by pathological examination，with a recurrence rate of 16% （16/100）， and 14 cases recurred by DCE-MRI examination， with a recurrence rate of 14% （14/100）.Compared with the results of pathological examination， there was a good consistency between DCE-MRI and pathological examination （Kappa=0.813， P=0.000）.

Conclusion

DCE-MRI has important value in the prognosis assessment of concurrent chemoradiotherapy for middle and advanced low rectal cancer，and is worth popularizing.