What CT and MRI findings indicate unresectability of pancreatic adenocarcinoma?
- • Tumor encasement of the arterial mesenteric vasculature (celiac artery, SMA, common hepatic artery). This is seen as obliteration of the normal fat around an artery, >180° of contact of tumor with an artery, or arterial luminal narrowing on cross-sectional imaging. If there is ≤ 180° of contact of tumor with an artery or short segment encasement of the common hepatic artery >1 cm from its origin, then the tumor may still be resectable.
- • Tumor encasement of the venous mesenteric vasculature (SMV, portal vein). This is seen as obliteration of the normal fat around a vein, >180 o of contact of tumor with a vein, venous luminal narrowing, or a teardrop configuration of the vein on cross-sectional imaging. Dilation of adjacent venous collaterals is also suggestive of unresectable tumor. If there is limited short segment nonocclusive involvement of the vein, then the tumor may still be resectable.
- • Presence of direct tumor invasion of organs (other than the duodenum).
- • Presence of distant metastatic disease (most often encountered in the liver, peritoneum, and nonregional lymph nodes, and less often seen in the lungs and bone marrow)
