Neuroendocrine tumors: role of interventional radiology in therapy

The management of neuroendocrine tumors (NETs) is complex. Although NETs can affect a variety of organ systems, hepatic metastatic disease in particular lends itself to a wide range of interventional treatment options. Prior detailed radiologic assessment and careful patient selection are required. Curative surgery should always be considered but is rarely possible. Embolization, radionuclide therapy, or ablative techniques may then be undertaken. Transcatheter arterial embolization (TAE) may be used alone or in combination with transcatheter arterial chemoembolization (TACE). NET type and extent of hepatic involvement are factors that can help predict the success of either TAE or TACE. Embolization techniques can also be useful in patients with nonhepatic NETs. Radionuclide therapy is emerging as a valuable adjunct and is dependent on positive somatostatin receptor status. Therapeutic radiopeptides may be delivered arterially. Ablative techniques have been shown to play a role in the palliation of symptoms and principally involve radiofrequency ablation. Hepatic cryotherapy and percutaneous ethanol injection have also been used. A multidisciplinary approach to treatment and follow-up is important. Imaging should involve dual-phase multidetector computed tomography and contrast material-enhanced magnetic resonance imaging. The role of the interventional radiologist will continue to expand as imaging techniques become more refined.