影像学检查在胃肠道间质瘤诊治中的应用价值及其进展

Application value of imaging methods and their progress in the diagnosis and treatment of gastrointestinal stromal tumors

胃肠道间质瘤(gastrointestinal stromal tumors,GISTs)是起源于消化道黏膜下层的间叶源性肿瘤,易向腔外生长.电子计算机X射线断层扫描技术(computed tomography,CT)和磁共振成像(magnetic resonance imaging,MRI)能准确判断GISTs的来源及与邻近器官的关系.易与腺癌、淋巴瘤、异位胰腺、囊肿及脂肪瘤相区别,但在影像学上却不能与其他间叶源性肿瘤相鉴别.其恶性生物学征象表现为肝转移、胃肠道壁浸润、体积大、不规则的表面、边界欠光整、不均匀强化和腹膜腔内播散,这些术前CT或MRI均可清楚显示.CT、MRI与正电子发射型计算机断层显像(positron emission computed tomography,PET)已成为格列卫靶向生物学治疗的疗效评估手段,其预测标准还需不断完善.

Gastrointestinal stromal tumors （GISTs） are a kind of mesenchymal tumors that originate from the submucosal layer of the gastrointestinal tract and show an exophytic growth pattern. CT and MRI are useful adjuncts in determining the site of origin of large GISTs and in assessing involvement of adjacent organs. GISTs can be easily differentiated from adenocarcinomas, lymphomas, ectopic pancreas, cystic lesions and lypomas. However, current imaging techniques are practically unable to distinguish GISTs from other mesenchymal tumors. Signs of malignant behavior of GISTs, which can be clearly presented on pre-operative CT or MRI, include liver metastasis, GI wall infiltration, large volume, irregular surface, illdefined margins, inhomogeneous enhancement and peritoneal spread. CT, MRI and positron emission computed tomography （PET-CT） have been effective methods in assessment of response to Gleevec treatment of GISTs, however, the standard is ought to be improved.