Abstract

The incidence of gallbladder cancer and biliary tract tumors has been increasing in recent years, with cholangiocarcinoma being the second most common primary liver malignancy. Accurate staging is crucial for determining the appropriate treatment strategy. Particularly in perihilar cholangiocarcinoma and infiltrative forms of biliary tract tumors, the sensitivity of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging for detecting primary lesions is not high and is not routinely recommended. FDG avidity may also be low in mucinous types of gallbladder cancers. Additionally, biliary stent placements and biliary infections can obscure cholangiocarcinoma foci or lead to false positive findings. However, in surgical candidates, PET/CT can be beneficial for ruling out distant metastases, evaluating suspicious findings in radiologic studies, assessing response to treatment in metastatic disease, and in cases of suspected recurrence. Although currently less accessible, studies have shown that PET/magnetic resonance imaging have identified additional findings that could alter patient management. Molecular imaging with Ga-68 fibroblast activation protein inhibitor, which targets the stromal component of the tumor microenvironment, has been found to have higher accuracy values than FDG for detecting both primary and metastatic lesions. This review discusses the role of molecular imaging in gallbladder and biliary tract tumors.