胃肠道间质瘤的诊断及磺酸伊马替尼疗效的CT评价

目的 观察GIST经酪氨酸激酶抑制剂甲磺酸伊马替尼（STI571）口服治疗后的CT改变并进行评估.方法 分析经病理学及免疫组织证实且资料完整GIST,并动态观察8例行STI571口服治疗后CT影像改变.结果 肿瘤发生于胃28例、小肠12例、十二指肠6例、结肠5例、直肠4例、肠系膜及食管各2例.瘤体较小时CT表现为向胃肠道壁腔内外生长的圆形或类圆形边界清楚的软组织密度肿块影,增强后明显均匀强化;瘤体较大时向胃肠道壁腔外纵向生长为主、呈间隙填充生长方式、形态不规则、部分边界不清的不均匀性密度肿块,增强后呈不均匀性强化,可见瘤体内血管及窦道形成.8例STI571治疗后,治疗期间随访时间2～22月,次数不等,CT改变①反应良好：肿瘤结节从不均质强化快速转为均质强化和肿块内血管消失、强化减弱、瘤体及瘤体内结节缩小、密度减低,本组5例;②反应意外：非出血或者粘液变性引起的瘤体及瘤体内结节增大、新出现内部结节,在原病变以外出现新病灶及转移灶,本组3例.结论 GIST的CT表现有一定特点;应用CT扫描观察测量病灶变化是评价STI571治疗GIST疗效最重要和最直接的方法之一;对指导临床治疗具有重要意义.

Gastrointestinal stromal tumor: role of spiral CT in diagnosis and evaluation of treatment with STI571

Objective To investigate the CT appearance of gastrointestinal stromal tumors （GISTs） after oral imatinib mesylate （STI571） treatment. Methods CT scans of 58 cases of GISTs proven by histology and immunohistochemistry were retrospectively analyzed. Dynamic contrast-enhanced CT of 8 patients after STI571 treatment was also evaluated. Results The tumors originated from the stomach （n=28）, small intestine （n=12）, duodenum （n=6）, colon （n=5）, rectum （n=4）, mesentery （n=2）, and esophagus （n=2）. Small GISTs appeared as round or oval, endo- or exophytic masses with well-defined margins and homogeneous contrast enhancement. Large lesions were often irregular infiltrative exnphytic masses with heterogeneous enhancement. U Iteration, fistulization and neovascularity can be seen within the larger tumors. CT scans of 5 patients with good treatment response showed rapid transition from a heterogeneously hyper-attenuating pattern to homogeneously hypo-attenuating pattern with resolution of the enhancing tumor nodules and decreased tumor neovascularity. In 3 poor responders, CT showed enlarging or new enhancing nodules within the treated hypo-attenuating tumor, new lesions or metastasis outside the primary tumor. Conclusion CT can demonstrate changes resulting from treatment of GISTs. It is valuable for guiding and assessing treatment response to STI571.