MRI和MSCT对进展期直肠癌新辅助疗效评估价值对比研究

目的 术前新辅助治疗现在已作为中低位进展期直肠癌的标准治疗模式,对于新辅助之后患者的分期评估尤为重要并且将决定患者的下一步治疗方案.本研究将探讨磁共振成像(magnetic resonance imaging,MRI)及多层螺旋CT(multisliecs helieal CT,MSCT)在评价术前新辅助放疗或同步放化疗(neoadjuvant chemoradiotherapy,NACRT)对中晚期低位直肠癌疗效的应用价值.方法 回顾性分析2011-01-01-2015-12-31新疆肿瘤医院经肠镜检查病理活检确诊的145例进展期中低位直肠癌患者,依据标准化NACRT前、后的盆腔MRI及MSCT资料分成实验组(MRI组)和对照组(MSCT组).分析NACRT前后MRI组和MSCT组上肿瘤的体积、TN分期、环周切缘(circumferential resection margin,CRM)的改变,并与术后病理结果分别进行对照.结果 MRI组NACRT后肿瘤完全缓解4例,部分缓解23例,稳定8例,进展3例,有效率为71.1％;MSCT组NACRT后肿瘤完全缓解16例,部分缓解63例,稳定17例,进展11例,有效率为72.0％,两组有效率比较,差异无统计学意义,x2=0.011,P＞0.05.MRI组术前T分期、CRM受侵情况的判断与术后病理结果一致性较好(Kappa-0.546、0.685),而N分期与术后病理结果一致性较差(Kappa=0.333);MSCT组术前T分期、CRM受累情况的判断与术后病理结果一致性较好(Kappa=0.503、0.650),而N分期与术后病理结果一致性较差(Kappa-0.299).两组影像学分期分别与术后病理结果进行对照比较:(1)T分期,两组比较差异无统计学意义,x2=1.287,P＞0.05;(2)N分期,两组比较差异无统计学意义,x2=0.154,P＞0.05;(3) CRM受累情况,两组比较差异无统计学意义,x2=0.344,P＞0.05.结论 NACRT可以有效缩小肿瘤的体积,降低肿瘤分期,但对CRM受侵情况并无明显改善.MRI和MSCT可以较为准确的判断肿瘤浸润程度,但对于淋巴结转移的检测准确性较差,MRI的一致性优于MSCT,但准确性无明显差异.

Comparative study on diagnostic value of MSCT and MRI in preoperative local staging for rectal cancer after neoadjuvant chemoradiotherapy

OBJECTIVE To investigate the diagnostic value of MSCT and MRI in preoperative local staging for advanced lower rectal cancer after standardized Neoadjuvant chemoradiotherapy.METHODS In 145 patients with locally advanced rectal cancer treated with preoperative CRT and surgery,two radiologists measured tumor volume on MSCT and MRI images before and after CRT.CT/MRI-based tumor volumetry and the modified response evaluation criteria in solid tumors (mRECISTs) were compared with T、N and CRM downstaging after CRT,and the tumor regression grade.RESULTS In MRI group,there were 4 cases of complete remission,23 cases of partial remission,8 cases of stabilization and 3 cases of progress after NACRT.The effective rate was 71.1％.On the MSCT,NACRT achieved complete remission in 16 cases,partial remission in 63 cases,stabilization in 17 cases and development in 11 cases;the effective rate was 72.0％.There was not any statistically significant difference between the two groups (x2 =0.011,P＞ 0.05).There was a great agreement between preoperative T stage and CRM invasion (P＜0.05).There was a fair agreement between preoperative T stage and postoperative pathological results (Kappa were 0.546 and 0.685).The same as MRI MSCT dose well in CRM and T stage (Kappa were 0.503 and 0.650).The MSCT preoperative N staging and the postoperative pathologic findings showed a lower consistency (Kappa=0.299,P＞0.05);N staging:There was no significant difference between the two groups (P＞ 0.05);There was no significant difference in the accuracy of the two groups (x2 =0.154,P＞0.05).There was no any statistical difference between the two groups (x2 =0.344,P＞0.05).CONCLUSIONS NACRT can effectively reduce the tumor size and tumor stage,but no significant improvement in CRM.MRI and MSCT can accurately judge the degree of tumor invasion,but for the accuracy of lymph node metastasis it is poor,and there is no significant difference between the two groups.Both of the two kind of imaging system can effectively evaluate the effect of neoadjuvant chemoradiotherapy.