摘要目的 分析局部晚期直肠癌术前放疗后影响预后的临床和影像学因素的研究.方法 回顾性分析2004年6月至2015年9月收治的符合入组标准的106例局部晚期并接受术前放疗的直肠癌患者.术后病理切片根据Mandard评分标准将肿瘤消退分级(TRG)分为肿瘤消退明显组(TRG1 +2)和肿瘤消退不明显组(TRG3 +4 +5).同时,利用磁共振扩散加权成像(DWI)技术测量放疗后肿瘤表观弥散系数(ADC),比较肿瘤ADC值与TRG之间的关系.结果 单因素分析中,年龄、化疗、pT分期、pN分期、分化程度、脉管癌栓以及TRG可能对总生存率(OS)有影响(x2=3.945 ～8.110,P＜0.05).多因素分析显示,分化程度和TRG是OS的独立预后因素(x2=5.221、6.563,P＜0.05).长程放疗组和短程放疗组之间的OS,差异无统计学意义(P＞0.05).肿瘤消退明显组(TRG1 +2)和肿瘤消退不明显组(TRG3 +4 +5)的5年OS分别为91.2％和67.4％,差异有统计学意义(x2=8.110,P＜0.05).术前放疗方式、术前化疗、病理类型、分化程度、大体类型、脉管癌栓和放疗后肿瘤ADC值对TRG有影响(x2=4.189～ 18.139,P＜0.05).利用ROC曲线找出放疗后肿瘤ADC值的最佳临界点1.7×10-3 mm2/s,放疗后肿瘤ADC值预测TRG1+2的准确性为70％.结论 Mandard TRG可预测局部晚期直肠癌患者术前放疗后的疗效.术前长程放疗和术前短程放疗之间的OS无明显差异.放疗后肿瘤ADC值可能可以预测局部晚期直肠癌的肿瘤消退情况.

abstractsObjective To explore the clinical and imaging factors influencing the patients' prognosis after preoperative radiotherapy for local advanced rectal cancer.Methods We retrospectively analyzed 106 locally advanced rectal cancer patients from June 2004 to September 2015 in our institution.All patients underwent preoperative radiotherapy.According to the Mandard score,patients were divided into 5 groups (TRG1-5).All patients were divided into two groups according to the TRG,which including good responder (TRG1 + 2) and poor responder (TRG3 + 4 + 5) groups.All of the tumor ADC values of post-RT were measured by Diffusion-weighted MRI technology,and the relationship between tumor ADC values of post-RT and TRG was analyzed.Results In univariate analysis,age,chemotherapy,pT,pN,differentiation degree,vascular invasion and TRG were significantly associated with overall survival (x2 =3.945-8.110,P ＜ 0.05).Multivariate analysis indicated that differentiation degree and TRG were the independent prognostic factors for OS (x2 =5.221,6.563,P ＜ 0.05).No significant difference was found between long-course and short-course radiotherapy group (P ＞ 0.05) in OS.The good responder group had a favorable survival in 5-year OS compared to the poor responder group (x2 =8.110,P ＜ 0.05).Preoperative radiotherapy,preoperative chemotherapy,pathological type,differentiation degree and gross type,vascular tumor thrombus and tumor ADC values of post-RT were significantly associated with TRG (x2 =4.189-18.139,P ＜ 0.05).The best critical point of tumor ADC values of post-RT was 1.7 x 10-3 mm2/s by using ROC curve.The accuracy of tumor ADC values of post-RT in predicting TRG1 + 2 was 70％.Conclusions The TRG can predict the efficacy of preoperative radiotherapy in patients with locally advanced rectal cancer based on the Mandard score.There was no significant difference in OS between long-course radiotherapy group and short-course radiotherapy group.The tumor ADC values of post-RT might become a potential factor to predict TRG in patients with locally advanced rectal cancer after preoperative radiotherapy.