2015 Update: Metastatic Neuroendocrine Tumors - Episode 3
Anatomic cross-sectional imaging, most commonly with CT or MRI, is the current imaging modality for pancreatic neuroendocrine tumors (pNETs), says James C. Yao, MD. Multiphasic CT scans are often performed, generally with arterial phase, venous phase, and non-contrast imaging, states Jonathan R. Strosberg, MD. MRI may be used to better delineate liver metastases, adds Strosberg.
Nuclear imaging may also be used to provide a global view of the tumors and how to proceed with treatment. Somatostatin receptor-based imaging, such as the OctreoScan, helps identify tumor location and confirm the presence of somatostatin receptors.
Surgery is generally considered upon initial evaluation of pNETs, if the tumor is nonmetastatic, says Strosberg. Resectability criteria include ensuring that the tumor does not involve major arteries, such as the celiac artery and superior mesenteric artery, or major veins, such as the portal vein or superior mesenteric vein. In some circumstances, the disease may be approached neoadjuvantly with cytotoxic regimens that will reduce the tumor size with the goal of proceeding with surgery afterwards. At this point in time, surgery is the only way to cure a patient, notes Matthew H. Kulke, MD.
Active surveillance may be discussed as an option in cases where the tumor is smaller than 2 centimeters, the patient is asymptomatic, and histology is consistent with a low-grade tumor. This strategy is more commonly employed in older individuals or patients with significant comorbidities, says Strosberg.