超声内镜对胰腺及壶腹癌术前分期及可切除性的评估

目的 观察超声内镜（EUS）诊断胰腺及壶腹部癌分期和血管侵犯的准确性和敏感性,并与术后病理结果进行比较,以确定其可切除及不可切除的预期值。方法 通过EUS扫描对42例胰腺癌和18例壶腹癌患者进行术前分期及血管侵犯的诊断。做好术前内镜检查准备后,持镜插入食管,至十二指肠降部,吸去肠、胃腔内的气体,依次注入脱气水200及500ml,以充盈肠及胃腔,有利超声传导。对胰头及壶腹各部结构进行超声扫描,并退镜至胃窦、胃体及胃底部,对胰头、胰体及胰尾部扫描,找见靶灶即摄片,供分析诊断。本组中的58例同时还进行了CT扫描。结果 （1）EUS的T分期准确率：胰腺癌的1、2、1、3、T4期分别为100．0％（5／5）、75．0％（9／12）和48．0％（12／25）,壶腹部癌的T1、1、2、1、3、T4期分别为75．0％（3／4）、66．7％（2／3）、75．0％（6／8）和33．3％（1／3）;N分期准确率：胰腺癌的N1和N0期分别为80．0％（4／5）和90．0％（9／10）;壶腹部癌的N1和N0期分别为50．0％（3／6）和91．0％（10／11）。（2）EUS及CT扫描对胰腺及壶腹部癌血管侵犯的诊断及其可切除与不可切除预期值的比较：60例EUS诊断的敏感性、特异性、可切除及不可切除预期值分别为52．9％（9／17）、93．1％（27／29）、77．1％（27／35）和8178％（9／11）;58例CT分别为11．8％（2／17）、92．6％（25／27）、62．5％（25／40）和50．0％（2／4）。结论 EUS是目前影像技术中诊断胰腺及壶腹部癌T分期及其血管侵犯最精确、敏感的方法之一;EUS分辨力高（7．5MHz=1．0mm）,可以发现胰腺及壶腹部≤2．0cm的小胰癌;但对胰腺及壶腹部癌的多发微小转移灶,则多不能发现。

Comparison of endoscopic ultrasonography with computer-assisted tomography in the determination of preoperative stage and resectability of pancreatic and ampullary cancers

OBJECTIVE: To study and compare the accuracy and sensitivity of endoscopic ultrasonography (EUS) and CT scaning in determination of preoperative stage and vascular invasion by pancreatic and ampullary cancers. METHODS: Fourty-two pancreatic cancer patients and 18 ampullary cancer patients were studied. With patients prepared according to conventional endoscopy, Olympus EUM-30 scope 1 set with a side view and 360 degrees rotate and switchable scanning probe [ultrasound frequency (7.5/12 MHz)], was introduced to the descending duodenum through the esophagus. Gas within the duodenum and stomach was aspirated. Then, in order to to facilitate ultrasound transmission, 200 ml deaerated water was injected into the duodenum and 500 ml into the stomach to distend it. The structures of each part of pancreatic head and ampullary together with surrounding vessels were scanned. Then, the scope was withdrawn to the gastric antrum, body and fundus gradually, while the pancreatic body and tail were scanned. RESULTS: Between Apr. 1996 to May 2004, a total of 42 pancreatic cancer patients and 18 ampullary cancer patients were examined by EUS. Meanwhile, all these 58 patients received preoperative CT scaning. The results of stage and vascular invasion determined by EUS in this series were as following; pancreatic cancer group (n = 42): accuracy in T2-4 stage was 100.0% (5/5), 75.0% (9/12) and 48.0% (12/25), respectively; ampullary cancer group (n = 18): T1-4 stage was 75.0% (3/4), 66.7% (2/3), 75.0% (6/8) and 33.3% (1/3), respectively; the accuracy in N stage: P-group: 80.0% in N1 (4/5), 90.0% in N0 (9/10); A-group: 50.0% in N1 (3/6), 91.0% in N0 (10/11). The sensitivity, specificity of vascular invasion, resectability and unresectablilty determined by EUS and CT as compared with surgical findings during operation was 52.9% (9/17), 93.1% (27/29), 77.1% (27/35) and 81.8% (9/11) for EUS (n = 60), respectively; and 11.8% (2/17), 92.6% (25/27), 62.5% (25/40) and 50.0% (2/4) for CT (n = 58), respectively. CONCLUSION: Endoscopic ultrosonography being one of the best image examinations to determine the stage and vascular invasion for pancreatic and ampullary cancer paitients is able to detect small pancreatic or ampullary cancer less than 2.0 cm in diameter due to its high resolution; but can not detect the secondary multiple distal metastases such as spread into the liver, peritonium or hepatoduodenal ligament, etc. due to its ultrasound depth limitation.