胃癌术前影像学精准分期存在的争议与困惑  

Controversy and confusion in preoperative imaging precise staging of gastric cancer

作　　者：唐磊[1] 

机构地区：[1]北京大学肿瘤医院暨北京市肿瘤防治研究所医学影像科恶性肿瘤发病机制及转化研究教育部重点实验室,100142

出　　处：《中华胃肠外科杂志》2016年第2期165-169,共5页Chinese Journal of Gastrointestinal Surgery

基　　金：基金项目：国家自然科学基金（81201215,81371715）;北京市自然科学基金（7132039）

摘　　要：AJCC规定了胃癌各分期的病理学标准，却没有描述各分期对应的影像学征象。权威标准的缺失以及现有影像手段的局限性，导致影像医生在胃癌评价时的＂分期恐惧＂（stage fright）以及不同认知下的争议与困惑：（1）胃黏膜下层未显示时只能采取＂50％厚度比＂的间接标准区分T1和T2。（2）影像学无法显示菲薄的浆膜下层，导致T2过分期为T3。（3）浆膜侧炎性纤维索条及胃裸区的存在，导致T3过分期为T4。（4） T4b的影像判断标准尚存争议，对其可切除性的认识也不统一；部分浸润显著、无法切除者，缺乏典型的CT征象。（5）体积仍是影像学判断淋巴结转移的直接标准，N分期准确率仅50%~70%。（6）早期腹膜转移缺乏特异性征象，诊断敏感性仅50%。针对上述胃癌术前精确分期面临的争议和困惑，现有影像学手段尚无法取得本质突破，但可通过检查和报告流程中的规范化（充盈、多期增强、多平面重建和窗技术等）、精细征象的发掘（亮线征和污迹征等）以及新手段的探索和利用（能谱CT和磁共振扩散成像等），在一定程度上得到改善和提高。AJCC determined the pathological standards for staging of gastric cancer, but no corresponding radiological signs of a single stage were described or documented. The vacancy of authority standards and limitation of the existing radiological modalities has caused the＂stage fright＂ of the radiologists during the clinical practices. The controversy and confusion under different cognitive aspects can be summarized as follows： （1）If the gastric submucosal layer is not detected, it can only take the indirect standard of ＂ 50% thickness ratio＂to distinguish T1 and T2. （2）T2 tumors may be overstaged as T3, as a result of the undetectable thin subserosa layer. （3） T3 tumors may be overstaged as T4, because of the inflammatory and fibrosis strands and spiculations near the serosa, and the existence of the gastric bare area. （4）The diagnostic imaging criteria for T4b are still controversial, and the opinions are not uniform about the resectable signs. Some significantly infiltrated unresectable tumors lack typical radiology signs. （5） Size is still the widely-used direct criterion for the diagnosis of lymph node metastasis, however the accuracy of N staging is only 50%-70%. （6）It lacks the typical sign for the diagnosis of early peritoneal metastasis, with a diagnostic sensitivity of only 50%. There is no fundamental breakthrough for the existing imaging modalities to solve the above controversies on the preoperative precise staging. However, the situations can be improved by standardization of the examination and reporting process （oral filling, multi-phase enhancement, multi planar reconstruction, and window width/level technique, etc.）, the exploration of the fine signs （hyperattenuating serosa sign, smudge sign, etc.） and the exploration of new modalities （spectral CT, diffusion weighted MR imaging, etc.）.

关 键 词：胃肿瘤 体层摄影术 X线计算机 磁共 振成像 肿瘤分期 

分 类 号：R735.2[医药卫生—肿瘤]