Endoluminal ultrasound for the diagnosis and staging of pancreatic cancer.
For pancreatic cancer, endosonography is at present the most accurate method of imaging, especially for detecting small lesions and assessing the extent of locoregional tumour spread. Although the overall accuracy of tumour detection is nearly 100%, differentiation between cancer and pseudotumours of inflammatory origin may sometimes present a problem. Clinical history, symptoms and other imaging techniques, particularly ERCP, should therefore always be considered. On the other hand, endosonography is indicated when the other imaging techniques are negative or doubtful in the presence of a high index of clinical suspicion. In cases with proven malignant tumours, it should be performed for proper staging. The overall accuracy of staging the primary tumour is 80-90%, whereas for detecting lymph nodes it is around 75%. In contrast to angiography, endosonography gives more detailed information of major vessel involvement, an important factor in deciding whether the tumour is resectable. Endosonography is, however, not suitable for the detection of distant metastasis due to the limited penetration of ultrasound. The newly developed echoduodenoscopes, equipped with a working channel and an elevator, provide the possibility for improved accuracy of biopsy under endosonographic guidance, and under clinical evaluation. This should further improve the differentiation between pancreatic cancer and inflammatory pseudotumours, which continues to be a significant clinical problem. So far no procedure-related complications of endosonography have been reported. An adequate experience in conventional ultrasound and endoscopy is essential, however, in order to achieve reliable results.
Grimm
H
H
Maydeo
A
A
Soehendra
N
N
D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000295:instrumentation; D019723:Endoscopes; D006801:Humans; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D011877:Radionuclide Imaging; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography / Q000295:instrumentation / Q000379:methods